diff --git a/.github/sync-repo-settings.yaml b/.github/sync-repo-settings.yaml
index ae4b07d122f..087d4a55617 100644
--- a/.github/sync-repo-settings.yaml
+++ b/.github/sync-repo-settings.yaml
@@ -11,9 +11,6 @@ branchProtectionRules:
     - 'Kokoro'
     - 'OwlBot Post Processor'
     - 'Samples - Lint'
-    - 'Samples - Python 3.7'
-    - 'Samples - Python 3.8'
-    - 'Samples - Python 3.9'
     - 'Samples - Python 3.10'
     - 'Samples - Python 3.11'
     - 'Samples - Python 3.12'
diff --git a/.kokoro/samples/lint/common.cfg b/.kokoro/samples/lint/common.cfg
index de81d49ddf3..26fd907aea7 100644
--- a/.kokoro/samples/lint/common.cfg
+++ b/.kokoro/samples/lint/common.cfg
@@ -21,14 +21,14 @@ env_vars: {
 # Configure the docker image for kokoro-trampoline.
 env_vars: {
     key: "TRAMPOLINE_IMAGE"
-    value: "gcr.io/cloud-devrel-kokoro-resources/python-samples-testing-docker"
+    value: "gcr.io/cloud-devrel-kokoro-resources/python-multi"
 }
 
 # Download secrets for samples
-gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/python-docs-samples"
+gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/google-cloud-python"
 
 # Download trampoline resources.
 gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/trampoline"
 
 # Use the trampoline script to run in docker.
-build_file: "google-api-python-client/.kokoro/trampoline_v2.sh"
\ No newline at end of file
+build_file: "google-api-python-client/.kokoro/trampoline.sh"
\ No newline at end of file
diff --git a/.kokoro/samples/python3.10/common.cfg b/.kokoro/samples/python3.10/common.cfg
index b1a684ce5f8..dc97e01456f 100644
--- a/.kokoro/samples/python3.10/common.cfg
+++ b/.kokoro/samples/python3.10/common.cfg
@@ -13,12 +13,6 @@ env_vars: {
     value: "py-3.10"
 }
 
-# Declare build specific Cloud project.
-env_vars: {
-    key: "BUILD_SPECIFIC_GCLOUD_PROJECT"
-    value: "python-docs-samples-tests-310"
-}
-
 env_vars: {
     key: "TRAMPOLINE_BUILD_FILE"
     value: "github/google-api-python-client/.kokoro/test-samples.sh"
@@ -27,14 +21,14 @@ env_vars: {
 # Configure the docker image for kokoro-trampoline.
 env_vars: {
     key: "TRAMPOLINE_IMAGE"
-    value: "gcr.io/cloud-devrel-kokoro-resources/python-samples-testing-docker"
+    value: "gcr.io/cloud-devrel-kokoro-resources/python-multi"
 }
 
 # Download secrets for samples
-gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/python-docs-samples"
+gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/google-cloud-python"
 
 # Download trampoline resources.
 gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/trampoline"
 
 # Use the trampoline script to run in docker.
-build_file: "google-api-python-client/.kokoro/trampoline_v2.sh"
\ No newline at end of file
+build_file: "google-api-python-client/.kokoro/trampoline.sh"
\ No newline at end of file
diff --git a/.kokoro/samples/python3.11/common.cfg b/.kokoro/samples/python3.11/common.cfg
index 0df5ac77f3a..bdc3170c104 100644
--- a/.kokoro/samples/python3.11/common.cfg
+++ b/.kokoro/samples/python3.11/common.cfg
@@ -13,12 +13,6 @@ env_vars: {
     value: "py-3.11"
 }
 
-# Declare build specific Cloud project.
-env_vars: {
-    key: "BUILD_SPECIFIC_GCLOUD_PROJECT"
-    value: "python-docs-samples-tests-311"
-}
-
 env_vars: {
     key: "TRAMPOLINE_BUILD_FILE"
     value: "github/google-api-python-client/.kokoro/test-samples.sh"
@@ -27,14 +21,14 @@ env_vars: {
 # Configure the docker image for kokoro-trampoline.
 env_vars: {
     key: "TRAMPOLINE_IMAGE"
-    value: "gcr.io/cloud-devrel-kokoro-resources/python-samples-testing-docker"
+    value: "gcr.io/cloud-devrel-kokoro-resources/python-multi"
 }
 
 # Download secrets for samples
-gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/python-docs-samples"
+gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/google-cloud-python"
 
 # Download trampoline resources.
 gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/trampoline"
 
 # Use the trampoline script to run in docker.
-build_file: "google-api-python-client/.kokoro/trampoline_v2.sh"
\ No newline at end of file
+build_file: "google-api-python-client/.kokoro/trampoline.sh"
\ No newline at end of file
diff --git a/.kokoro/samples/python3.12/common.cfg b/.kokoro/samples/python3.12/common.cfg
index 3d6669cf426..29cf43c31c7 100644
--- a/.kokoro/samples/python3.12/common.cfg
+++ b/.kokoro/samples/python3.12/common.cfg
@@ -13,12 +13,6 @@ env_vars: {
     value: "py-3.12"
 }
 
-# Declare build specific Cloud project.
-env_vars: {
-    key: "BUILD_SPECIFIC_GCLOUD_PROJECT"
-    value: "python-docs-samples-tests-312"
-}
-
 env_vars: {
     key: "TRAMPOLINE_BUILD_FILE"
     value: "github/google-api-python-client/.kokoro/test-samples.sh"
@@ -27,14 +21,14 @@ env_vars: {
 # Configure the docker image for kokoro-trampoline.
 env_vars: {
     key: "TRAMPOLINE_IMAGE"
-    value: "gcr.io/cloud-devrel-kokoro-resources/python-samples-testing-docker"
+    value: "gcr.io/cloud-devrel-kokoro-resources/python-multi"
 }
 
 # Download secrets for samples
-gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/python-docs-samples"
+gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/google-cloud-python"
 
 # Download trampoline resources.
 gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/trampoline"
 
 # Use the trampoline script to run in docker.
-build_file: "google-api-python-client/.kokoro/trampoline_v2.sh"
\ No newline at end of file
+build_file: "google-api-python-client/.kokoro/trampoline.sh"
\ No newline at end of file
diff --git a/.kokoro/samples/python3.13/common.cfg b/.kokoro/samples/python3.13/common.cfg
index 25f2a9ed5ec..ac97d8948d8 100644
--- a/.kokoro/samples/python3.13/common.cfg
+++ b/.kokoro/samples/python3.13/common.cfg
@@ -13,12 +13,6 @@ env_vars: {
     value: "py-3.13"
 }
 
-# Declare build specific Cloud project.
-env_vars: {
-    key: "BUILD_SPECIFIC_GCLOUD_PROJECT"
-    value: "python-docs-samples-tests-313"
-}
-
 env_vars: {
     key: "TRAMPOLINE_BUILD_FILE"
     value: "github/google-api-python-client/.kokoro/test-samples.sh"
@@ -27,14 +21,14 @@ env_vars: {
 # Configure the docker image for kokoro-trampoline.
 env_vars: {
     key: "TRAMPOLINE_IMAGE"
-    value: "gcr.io/cloud-devrel-kokoro-resources/python-samples-testing-docker"
+    value: "gcr.io/cloud-devrel-kokoro-resources/python-multi"
 }
 
 # Download secrets for samples
-gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/python-docs-samples"
+gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/google-cloud-python"
 
 # Download trampoline resources.
 gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/trampoline"
 
 # Use the trampoline script to run in docker.
-build_file: "google-api-python-client/.kokoro/trampoline_v2.sh"
+build_file: "google-api-python-client/.kokoro/trampoline.sh"
diff --git a/.kokoro/samples/python3.14/common.cfg b/.kokoro/samples/python3.14/common.cfg
index e9d0480a348..bd5ecb260aa 100644
--- a/.kokoro/samples/python3.14/common.cfg
+++ b/.kokoro/samples/python3.14/common.cfg
@@ -13,12 +13,6 @@ env_vars: {
     value: "py-3.14"
 }
 
-# Declare build specific Cloud project.
-env_vars: {
-    key: "BUILD_SPECIFIC_GCLOUD_PROJECT"
-    value: "python-docs-samples-tests-314"
-}
-
 env_vars: {
     key: "TRAMPOLINE_BUILD_FILE"
     value: "github/google-api-python-client/.kokoro/test-samples.sh"
@@ -27,14 +21,14 @@ env_vars: {
 # Configure the docker image for kokoro-trampoline.
 env_vars: {
     key: "TRAMPOLINE_IMAGE"
-    value: "gcr.io/cloud-devrel-kokoro-resources/python-samples-testing-docker"
+    value: "gcr.io/cloud-devrel-kokoro-resources/python-multi"
 }
 
 # Download secrets for samples
-gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/python-docs-samples"
+gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/google-cloud-python"
 
 # Download trampoline resources.
 gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/trampoline"
 
 # Use the trampoline script to run in docker.
-build_file: "google-api-python-client/.kokoro/trampoline_v2.sh"
+build_file: "google-api-python-client/.kokoro/trampoline.sh"
diff --git a/.kokoro/samples/python3.7/common.cfg b/.kokoro/samples/python3.7/common.cfg
deleted file mode 100644
index 51153192905..00000000000
--- a/.kokoro/samples/python3.7/common.cfg
+++ /dev/null
@@ -1,40 +0,0 @@
-# Format: //devtools/kokoro/config/proto/build.proto
-
-# Build logs will be here
-action {
-  define_artifacts {
-    regex: "**/*sponge_log.xml"
-  }
-}
-
-# Specify which tests to run
-env_vars: {
-    key: "RUN_TESTS_SESSION"
-    value: "py-3.7"
-}
-
-# Declare build specific Cloud project.
-env_vars: {
-    key: "BUILD_SPECIFIC_GCLOUD_PROJECT"
-    value: "python-docs-samples-tests-py37"
-}
-
-env_vars: {
-    key: "TRAMPOLINE_BUILD_FILE"
-    value: "github/google-api-python-client/.kokoro/test-samples.sh"
-}
-
-# Configure the docker image for kokoro-trampoline.
-env_vars: {
-    key: "TRAMPOLINE_IMAGE"
-    value: "gcr.io/cloud-devrel-kokoro-resources/python-samples-testing-docker"
-}
-
-# Download secrets for samples
-gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/python-docs-samples"
-
-# Download trampoline resources.
-gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/trampoline"
-
-# Use the trampoline script to run in docker.
-build_file: "google-api-python-client/.kokoro/trampoline_v2.sh"
\ No newline at end of file
diff --git a/.kokoro/samples/python3.7/continuous.cfg b/.kokoro/samples/python3.7/continuous.cfg
deleted file mode 100644
index a1c8d9759c8..00000000000
--- a/.kokoro/samples/python3.7/continuous.cfg
+++ /dev/null
@@ -1,6 +0,0 @@
-# Format: //devtools/kokoro/config/proto/build.proto
-
-env_vars: {
-    key: "INSTALL_LIBRARY_FROM_SOURCE"
-    value: "True"
-}
\ No newline at end of file
diff --git a/.kokoro/samples/python3.7/periodic-head.cfg b/.kokoro/samples/python3.7/periodic-head.cfg
deleted file mode 100644
index fff273b4711..00000000000
--- a/.kokoro/samples/python3.7/periodic-head.cfg
+++ /dev/null
@@ -1,11 +0,0 @@
-# Format: //devtools/kokoro/config/proto/build.proto
-
-env_vars: {
-    key: "INSTALL_LIBRARY_FROM_SOURCE"
-    value: "True"
-}
-
-env_vars: {
-    key: "TRAMPOLINE_BUILD_FILE"
-    value: "github/google-api-python-client/.kokoro/test-samples-against-head.sh"
-}
diff --git a/.kokoro/samples/python3.7/periodic.cfg b/.kokoro/samples/python3.7/periodic.cfg
deleted file mode 100644
index 71cd1e597e3..00000000000
--- a/.kokoro/samples/python3.7/periodic.cfg
+++ /dev/null
@@ -1,6 +0,0 @@
-# Format: //devtools/kokoro/config/proto/build.proto
-
-env_vars: {
-    key: "INSTALL_LIBRARY_FROM_SOURCE"
-    value: "False"
-}
diff --git a/.kokoro/samples/python3.7/presubmit.cfg b/.kokoro/samples/python3.7/presubmit.cfg
deleted file mode 100644
index a1c8d9759c8..00000000000
--- a/.kokoro/samples/python3.7/presubmit.cfg
+++ /dev/null
@@ -1,6 +0,0 @@
-# Format: //devtools/kokoro/config/proto/build.proto
-
-env_vars: {
-    key: "INSTALL_LIBRARY_FROM_SOURCE"
-    value: "True"
-}
\ No newline at end of file
diff --git a/.kokoro/samples/python3.8/common.cfg b/.kokoro/samples/python3.8/common.cfg
deleted file mode 100644
index 51397da6b2b..00000000000
--- a/.kokoro/samples/python3.8/common.cfg
+++ /dev/null
@@ -1,40 +0,0 @@
-# Format: //devtools/kokoro/config/proto/build.proto
-
-# Build logs will be here
-action {
-  define_artifacts {
-    regex: "**/*sponge_log.xml"
-  }
-}
-
-# Specify which tests to run
-env_vars: {
-    key: "RUN_TESTS_SESSION"
-    value: "py-3.8"
-}
-
-# Declare build specific Cloud project.
-env_vars: {
-    key: "BUILD_SPECIFIC_GCLOUD_PROJECT"
-    value: "python-docs-samples-tests-py38"
-}
-
-env_vars: {
-    key: "TRAMPOLINE_BUILD_FILE"
-    value: "github/google-api-python-client/.kokoro/test-samples.sh"
-}
-
-# Configure the docker image for kokoro-trampoline.
-env_vars: {
-    key: "TRAMPOLINE_IMAGE"
-    value: "gcr.io/cloud-devrel-kokoro-resources/python-samples-testing-docker"
-}
-
-# Download secrets for samples
-gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/python-docs-samples"
-
-# Download trampoline resources.
-gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/trampoline"
-
-# Use the trampoline script to run in docker.
-build_file: "google-api-python-client/.kokoro/trampoline_v2.sh"
\ No newline at end of file
diff --git a/.kokoro/samples/python3.8/continuous.cfg b/.kokoro/samples/python3.8/continuous.cfg
deleted file mode 100644
index a1c8d9759c8..00000000000
--- a/.kokoro/samples/python3.8/continuous.cfg
+++ /dev/null
@@ -1,6 +0,0 @@
-# Format: //devtools/kokoro/config/proto/build.proto
-
-env_vars: {
-    key: "INSTALL_LIBRARY_FROM_SOURCE"
-    value: "True"
-}
\ No newline at end of file
diff --git a/.kokoro/samples/python3.8/periodic-head.cfg b/.kokoro/samples/python3.8/periodic-head.cfg
deleted file mode 100644
index fff273b4711..00000000000
--- a/.kokoro/samples/python3.8/periodic-head.cfg
+++ /dev/null
@@ -1,11 +0,0 @@
-# Format: //devtools/kokoro/config/proto/build.proto
-
-env_vars: {
-    key: "INSTALL_LIBRARY_FROM_SOURCE"
-    value: "True"
-}
-
-env_vars: {
-    key: "TRAMPOLINE_BUILD_FILE"
-    value: "github/google-api-python-client/.kokoro/test-samples-against-head.sh"
-}
diff --git a/.kokoro/samples/python3.8/periodic.cfg b/.kokoro/samples/python3.8/periodic.cfg
deleted file mode 100644
index 71cd1e597e3..00000000000
--- a/.kokoro/samples/python3.8/periodic.cfg
+++ /dev/null
@@ -1,6 +0,0 @@
-# Format: //devtools/kokoro/config/proto/build.proto
-
-env_vars: {
-    key: "INSTALL_LIBRARY_FROM_SOURCE"
-    value: "False"
-}
diff --git a/.kokoro/samples/python3.8/presubmit.cfg b/.kokoro/samples/python3.8/presubmit.cfg
deleted file mode 100644
index a1c8d9759c8..00000000000
--- a/.kokoro/samples/python3.8/presubmit.cfg
+++ /dev/null
@@ -1,6 +0,0 @@
-# Format: //devtools/kokoro/config/proto/build.proto
-
-env_vars: {
-    key: "INSTALL_LIBRARY_FROM_SOURCE"
-    value: "True"
-}
\ No newline at end of file
diff --git a/.kokoro/samples/python3.9/common.cfg b/.kokoro/samples/python3.9/common.cfg
deleted file mode 100644
index 7afd4f279ee..00000000000
--- a/.kokoro/samples/python3.9/common.cfg
+++ /dev/null
@@ -1,40 +0,0 @@
-# Format: //devtools/kokoro/config/proto/build.proto
-
-# Build logs will be here
-action {
-  define_artifacts {
-    regex: "**/*sponge_log.xml"
-  }
-}
-
-# Specify which tests to run
-env_vars: {
-    key: "RUN_TESTS_SESSION"
-    value: "py-3.9"
-}
-
-# Declare build specific Cloud project.
-env_vars: {
-    key: "BUILD_SPECIFIC_GCLOUD_PROJECT"
-    value: "python-docs-samples-tests-py39"
-}
-
-env_vars: {
-    key: "TRAMPOLINE_BUILD_FILE"
-    value: "github/google-api-python-client/.kokoro/test-samples.sh"
-}
-
-# Configure the docker image for kokoro-trampoline.
-env_vars: {
-    key: "TRAMPOLINE_IMAGE"
-    value: "gcr.io/cloud-devrel-kokoro-resources/python-samples-testing-docker"
-}
-
-# Download secrets for samples
-gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/python-docs-samples"
-
-# Download trampoline resources.
-gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/trampoline"
-
-# Use the trampoline script to run in docker.
-build_file: "google-api-python-client/.kokoro/trampoline_v2.sh"
\ No newline at end of file
diff --git a/.kokoro/samples/python3.9/continuous.cfg b/.kokoro/samples/python3.9/continuous.cfg
deleted file mode 100644
index a1c8d9759c8..00000000000
--- a/.kokoro/samples/python3.9/continuous.cfg
+++ /dev/null
@@ -1,6 +0,0 @@
-# Format: //devtools/kokoro/config/proto/build.proto
-
-env_vars: {
-    key: "INSTALL_LIBRARY_FROM_SOURCE"
-    value: "True"
-}
\ No newline at end of file
diff --git a/.kokoro/samples/python3.9/periodic-head.cfg b/.kokoro/samples/python3.9/periodic-head.cfg
deleted file mode 100644
index fff273b4711..00000000000
--- a/.kokoro/samples/python3.9/periodic-head.cfg
+++ /dev/null
@@ -1,11 +0,0 @@
-# Format: //devtools/kokoro/config/proto/build.proto
-
-env_vars: {
-    key: "INSTALL_LIBRARY_FROM_SOURCE"
-    value: "True"
-}
-
-env_vars: {
-    key: "TRAMPOLINE_BUILD_FILE"
-    value: "github/google-api-python-client/.kokoro/test-samples-against-head.sh"
-}
diff --git a/.kokoro/samples/python3.9/periodic.cfg b/.kokoro/samples/python3.9/periodic.cfg
deleted file mode 100644
index 71cd1e597e3..00000000000
--- a/.kokoro/samples/python3.9/periodic.cfg
+++ /dev/null
@@ -1,6 +0,0 @@
-# Format: //devtools/kokoro/config/proto/build.proto
-
-env_vars: {
-    key: "INSTALL_LIBRARY_FROM_SOURCE"
-    value: "False"
-}
diff --git a/.kokoro/samples/python3.9/presubmit.cfg b/.kokoro/samples/python3.9/presubmit.cfg
deleted file mode 100644
index a1c8d9759c8..00000000000
--- a/.kokoro/samples/python3.9/presubmit.cfg
+++ /dev/null
@@ -1,6 +0,0 @@
-# Format: //devtools/kokoro/config/proto/build.proto
-
-env_vars: {
-    key: "INSTALL_LIBRARY_FROM_SOURCE"
-    value: "True"
-}
\ No newline at end of file
diff --git a/.kokoro/test-samples-against-head.sh b/.kokoro/test-samples-against-head.sh
index e9d8bd79a64..5bbb6a71f2a 100755
--- a/.kokoro/test-samples-against-head.sh
+++ b/.kokoro/test-samples-against-head.sh
@@ -23,4 +23,7 @@ set -eo pipefail
 # Enables `**` to include files nested inside sub-folders
 shopt -s globstar
 
+export PROJECT_ROOT=$(realpath $(dirname "${BASH_SOURCE[0]}")/..)
+cd "${PROJECT_ROOT}"
+
 exec .kokoro/test-samples-impl.sh
diff --git a/.kokoro/test-samples-impl.sh b/.kokoro/test-samples-impl.sh
index 53e365bc4e7..d61e7b6ebe2 100755
--- a/.kokoro/test-samples-impl.sh
+++ b/.kokoro/test-samples-impl.sh
@@ -13,11 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-
-# `-e` enables the script to automatically fail when a command fails
-# `-o pipefail` sets the exit code to the rightmost comment to exit with a non-zero
 set -eo pipefail
-# Enables `**` to include files nested inside sub-folders
 shopt -s globstar
 
 # Exit early if samples don't exist
@@ -33,42 +29,32 @@ export PYTHONUNBUFFERED=1
 env | grep KOKORO
 
 # Install nox
-# `virtualenv==20.26.6` is added for Python 3.7 compatibility
-python3.9 -m pip install --upgrade --quiet nox virtualenv==20.26.6
 
-# Use secrets acessor service account to get secrets
-if [[ -f "${KOKORO_GFILE_DIR}/secrets_viewer_service_account.json" ]]; then
-    gcloud auth activate-service-account \
-	   --key-file="${KOKORO_GFILE_DIR}/secrets_viewer_service_account.json" \
-	   --project="cloud-devrel-kokoro-resources"
+# Setup project id.
+if [[ -f "${KOKORO_GFILE_DIR}/project-id.json" ]]; then
+  export PROJECT_ID=$(cat "${KOKORO_GFILE_DIR}/project-id.json")
+  export GOOGLE_CLOUD_PROJECT="${PROJECT_ID}"
+  gcloud config set project "$PROJECT_ID"
+  
+  # Compute tests require CLOUD_STORAGE_BUCKET. We reuse a fixed bucket name
+  # within the project so it doesn't leak thousands of buckets over time.
+  export CLOUD_STORAGE_BUCKET="${PROJECT_ID}-api-client-compute"
 fi
 
-# This script will create 3 files:
-# - testing/test-env.sh
-# - testing/service-account.json
-# - testing/client-secrets.json
-./scripts/decrypt-secrets.sh
-
-source ./testing/test-env.sh
-export GOOGLE_APPLICATION_CREDENTIALS=$(pwd)/testing/service-account.json
-
-# For cloud-run session, we activate the service account for gcloud sdk.
-gcloud auth activate-service-account \
-       --key-file "${GOOGLE_APPLICATION_CREDENTIALS}"
-
-export GOOGLE_CLIENT_SECRETS=$(pwd)/testing/client-secrets.json
+# Setup service account credentials.
+if [[ -f "${KOKORO_GFILE_DIR}/service-account.json" ]]; then
+  export GOOGLE_APPLICATION_CREDENTIALS="${KOKORO_GFILE_DIR}/service-account.json"
+  gcloud auth activate-service-account --key-file="${GOOGLE_APPLICATION_CREDENTIALS}"
+fi
 
 echo -e "\n******************** TESTING PROJECTS ********************"
 
-# Switch to 'fail at end' to allow all tests to complete before exiting.
 set +e
-# Use RTN to return a non-zero value if the test fails.
 RTN=0
 ROOT=$(pwd)
 # Find all requirements.txt in the samples directory (may break on whitespace).
 for file in samples/**/requirements.txt; do
     cd "$ROOT"
-    # Navigate to the project folder.
     file=$(dirname "$file")
     cd "$file"
 
@@ -76,12 +62,9 @@ for file in samples/**/requirements.txt; do
     echo "- testing $file"
     echo "------------------------------------------------------------"
 
-    # Use nox to execute the tests for the project.
-    python3.9 -m nox -s "$RUN_TESTS_SESSION"
+    python3 -m nox -s "$RUN_TESTS_SESSION"
     EXIT=$?
 
-    # If this is a periodic build, send the test log to the FlakyBot.
-    # See https://github.com/googleapis/repo-automation-bots/tree/main/packages/flakybot.
     if [[ $KOKORO_BUILD_ARTIFACTS_SUBDIR = *"periodic"* ]]; then
       chmod +x $KOKORO_GFILE_DIR/linux_amd64/flakybot
       $KOKORO_GFILE_DIR/linux_amd64/flakybot
@@ -93,11 +76,7 @@ for file in samples/**/requirements.txt; do
     else
       echo -e "\n Testing completed.\n"
     fi
-
 done
-cd "$ROOT"
-
-# Workaround for Kokoro permissions issue: delete secrets
-rm testing/{test-env.sh,client-secrets.json,service-account.json}
 
+cd "$ROOT"
 exit "$RTN"
diff --git a/.kokoro/test-samples.sh b/.kokoro/test-samples.sh
index 7933d820149..e537eace360 100755
--- a/.kokoro/test-samples.sh
+++ b/.kokoro/test-samples.sh
@@ -24,6 +24,9 @@ set -eo pipefail
 # Enables `**` to include files nested inside sub-folders
 shopt -s globstar
 
+export PROJECT_ROOT=$(realpath $(dirname "${BASH_SOURCE[0]}")/..)
+cd "${PROJECT_ROOT}"
+
 # Run periodic samples tests at latest release
 if [[ $KOKORO_BUILD_ARTIFACTS_SUBDIR = *"periodic"* ]]; then
     # preserving the test runner implementation.
diff --git a/owlbot.py b/owlbot.py
index e0b39f67489..7ee3d49cf8e 100644
--- a/owlbot.py
+++ b/owlbot.py
@@ -37,7 +37,7 @@
 )
 
 # Copy kokoro configs.
-s.move(templated_files / ".kokoro")
+s.move(templated_files / ".kokoro", excludes=["samples/**", "test-samples*.sh"])
 s.move(templated_files / ".trampolinerc")  # config file for trampoline_v2
 
 # Also move issue templates