Applying SP3 to Cluster SQL server which is in Peer to Peer Replication

Hi all,

I have a situation to apply SP3 to  SQL Server 2008R2 which has Peer to Peer replication.

Present version: SQL Server 2008R2 SP1

Please suggest <g class="gr_ gr_285 gr-alert gr_gramm gr_run_anim Grammar only-ins replaceWithoutSep" data-gr-id="285" id="285">best</g> way  to apply the SP3 on Peer to Peer replication servers on SQL Server 2008R2

Turn off replication on both servers.
Make sure full backup in place 
Apply SP3
Reboot servers.
Turn on replication.

or

Apply SP3 to Distributor

Apply SP3 to Publisher

Apply SP3 to Subscriber

Thanks in advance

SNIVAS