diff --git a/howto/code/index.rst b/howto/code/index.rst
index 998109c..3041736 100644
--- a/howto/code/index.rst
+++ b/howto/code/index.rst
@@ -8,3 +8,4 @@
    job-failures
    linting
    pull_request
+   voltha-protos
diff --git a/howto/code/voltha-protos.rst b/howto/code/voltha-protos.rst
new file mode 100644
index 0000000..2403b63
--- /dev/null
+++ b/howto/code/voltha-protos.rst
@@ -0,0 +1,96 @@
+Modifying repository voltha-protos
+==================================
+
+#. Clone repository `voltha-protos <https://gerrit.opencord.org/plugins/gitiles/voltha-protos/+/refs/heads/master>`_
+#. Modify structures, sources & makefiles as needed.
+#. Build, test and lint locally to validate sources.
+#. Commit changes, code review, jenins build and deploy.
+#. Update external dependent repositories to use the new version.
+
+Clone, edit, build & test
+-------------------------
+
+.. code:: bash
+
+    git clone ssh://gerrit.opencord.org:29418/voltha-protos.git
+    cd voltha-protos
+    vi ...
+
+    make build
+    make test
+    make lint
+
+.. list-table:: Build & Test locally
+   :widths: 30, 80
+   :header-rows: 1
+
+   * - Command
+     - Description
+   * - make sterile
+     - Remove previously generated targets
+   * - make protos
+     - Generate prototypes for go, java & python (dependency for target:build)
+   * - make build
+     - make protos; compile: go, java & python
+   * - make test
+     - Validate proto changes
+   * - make lint
+     - Syntax check sources prior to commit.
+
+Update all external repositories to consume the new repo:voltha-protos version
+------------------------------------------------------------------------------
+
+- Each external VOLTHA repository will need to have dependencies mentioned in
+  the file go.mod updated.
+- Rebuild each repository in hierarchial order also updating external libs as
+  they are rebuilt.
+
+.. list-table:: External repositories to modify
+   :widths: 30, 80
+   :header-rows: 1
+
+   * - Repository
+     - File(s) to edit
+   * - bbsim
+     - `go.mod <https://gerrit.opencord.org/plugins/gitiles/bbsim/+/refs/heads/master/go.mod>`_
+   * - ofagent-go
+     - `go.mod <https://gerrit.opencord.org/plugins/gitiles/ofagent-go/+/refs/heads/master/go.mod>`__
+   * - voltctl
+     - `go.mod <https://gerrit.opencord.org/plugins/gitiles/voltctl/+/refs/heads/master/go.mod>`__
+   * - voltha-go
+     - `go.mod <https://gerrit.opencord.org/plugins/gitiles/voltha-go/+/refs/heads/master/go.mod>`__
+   * - voltha-go-controller
+     - `go.mod <https://gerrit.opencord.org/plugins/gitiles/voltha-go-controller/+/refs/heads/master/go.mod>`__
+   * - voltha-lib-go
+     - `go.mod <https://gerrit.opencord.org/plugins/gitiles/voltha-lib-go/+/refs/heads/master/go.mod>`__
+   * - voltha-openolt-adapter
+     - `go.mod <https://gerrit.opencord.org/plugins/gitiles/voltha-openolt-adapter/+/refs/heads/master/go.mod>`__
+   * - voltha-openonu-adapter-go
+     - `go.mod <https://gerrit.opencord.org/plugins/gitiles/voltha-openonu-adapter-go/+/refs/heads/master/go.mod>`__
+   * - voltha-system-tests
+     - `requirements.txt <https://gerrit.opencord.org/plugins/gitiles/voltha-system-tests/+/refs/heads/master/requirements.txt>`_ (virtualenv/testing)
+
+.. list-table:: Foreach external repository
+   :widths: 30, 80
+   :header-rows: 1
+
+   * - Command
+     - Description
+   * - vi {repo}/go.mod
+     - Bump version of repo:voltha-proto to latest published
+   * - vi {repo}/go.mod
+     - Bump external module version(s) during hierarcical build.
+   * - go mod edit -replace [...]
+     - Use the go mod tool to update version of voltha-protos and friends.
+   * - go mod tidy
+     - Cleanup syntax issues in golang source that will fail your pending commit
+   * - go mod vendor
+     - | Update sources and dependencies beneath the vendor/ directory.
+       | See also `go-mod-vendor <https://go.dev/ref/mod#go-mod-vendor>`_, `Packages & Modules <https://golangbyexample.com/packages-modules-go-second/>`_
+   * - make build
+     - Compile with updated module dependencies.
+   * - make test
+     - Sanity check everything is still working.
+   * - make lint LOCAL_FIX_PERMS=1
+     - | Syntax check sources for problems prior to checkin.
+       | LOCAL_FIX_PERMS=1 (optional) can workaround docker related permission problems.