Consolidating CAS and MBX servers into one

I have a server running the CAS role and another running the Mailbox role. I need to consolidate both into one. Any idea on the steps to migrate the mailbox role onto the CAS server? Is it as simple as:

1. Install Mailbox role on the CAS server (the cas server currently does not have the mailbox role)
2. Add this now to the DAG
3. Make it active
4. Make the old mailbox server passive
5. Then uninstall exchange from the old mailbox server

I also have two other similar servers setup across the WAN, if the procedure above works then I will apply same to the other servers.

Vijay