Add steps for post merge cleanup

enhancements/storage/csi-driver-operator-merge.md

@@ -533,6 +533,16 @@ But once your operator has been changed to conform to new code in csi-operator r
 
 Please note the changes to `ocp-build-data`should be merged almost same time as changes into `csi-operator`'s Dockerfile are merged, otherwise we risk builds from breaking.
 
+### Post migration changes
+
+Once migration is complete, we should perform following post migration steps to ensure that we are not left over with legacy stuff:
+
+1. Mark existing `openshift/<vendor>-<driver>-operator` repository as deprecated.
+2. Ensure that we have test manifest available in `test/e2e2` directory.
+3. Make changes into `release` repository so as it longer relies on anything from `legacy` directory. See - https://github.com/openshift/release/pull/49655 for example.
+4. Remove code from `vendor/legacy` in `csi-operator` repository. 
+
+
 ## Implementation History
 
 Major milestones in the life cycle of a proposal should be tracked in `Implementation