Which five actions should you perform in sequence before you can add EX2 to DAG2?

Explanation/Reference:
Note:
Box 1: Add EX5 to DAG1
We need to add EX5 to DAG1 for redundancy before we remove EX2.
Box 2: Create Mailbox database copies on EX5
We must set up EX5 mailbox database copies for redundancy before we remove EX2.
Box 3: On EX2, remove all of the mailbox database copies.
We remove the DAG1 mailbox database copies from EX2. We must do this before removing EX2 from DAG1 as the Mailbox server must not host any replicated databases when it is removed.
Box 4: Remove EX2 from DAG1
Now can when EX5 being set up for DAG1 we can remove EX2 from DAG1.
Box 5: On EX2 install Windows Server 2012 R2 and Exchange Server 2013
As the other members of DAG2 run Windows Server 2012 R2 datacenter we upgrade EX2 to Windows Server 2012 R2 as well.
Incorrect answers:
* There is no need to disable DAG replication for DAG1.
* There is no need to remove the DAG network from DAG1.
* Nothing would be accomplished by renaming EX5 to EX2.
Reference: https://technet.microsoft.com/en-us/library/dd297956%28v=exchg.150%29.aspx