Update docs for Kubernetes go modules upgrade

docs/dependency-management.md

@@ -18,7 +18,29 @@ To upgrade to the latest version for all direct and indirect dependencies of the
 * run `go get -u=patch <package>` to use the latest patch releases
 * run `go get <pacakge>@VERSION` to use the specified version
 
-You can also manually editing `go.mod`.
+You can also manually editing `go.mod` and update the versions in `require` and `replace` parts.
+
+Because of staging in Kubernetes, manually `go.mod` updating is required for Kubernetes and
+its staging packages. In cloud-provider-azure, their versions are set in `replace` part, e.g.
+
+```go
+replace (
+    ...
+    k8s.io/kubernetes => k8s.io/kubernetes v0.0.0-20190815230911-4e7fd98763aa
+    k8s.io/legacy-cloud-providers => k8s.io/kubernetes/staging/src/k8s.io/legacy-cloud-providers v0.0.0-20190815230911-4e7fd98763aa
+)
+```
+
+To update their versions, you need switch to `$GOPATH/src/k8s.io/kubernetes`, checkout to
+the version you want upgrade to, and finally run the following commands to get the go modules expected version:
+
+```sh
+commit=$(git log --date=format:'%Y%m%d%H%M%S' -1 | head -n 1 | awk '{print $2}' | cut -c1-12)
+date=$(git log --date=format:'%Y%m%d%H%M%S' -1 | awk '/Date:/{print $2}')
+echo "v0.0.0-$date-$commit"
+```
+
+After this, replace all kubernetes and staging versions (e.g. `v0.0.0-20190815230911-4e7fd98763aa` in above example) in `go.mod`.
 
 Always run `hack/update-dependencies.sh` after changing `go.mod` by any of these methods (or adding new imports).