Cloning and Replication

We currently have and ER domain with both IDS 11.7 servers and IDS 11.5 servers. We are migrating away from all 11.5 servers and replacing with 11.7 (on new hardware). I want to use ifx_clone.. and set up a grid. I understand that I need to remove the 11.5 servers from the domain before cloning to make things cleaner. My question is this... do I need to delete the ER server from my one main primary 11.7 server before I clone, then recreate all the replication? then create the grid? or can just remove all the other servers, so that there will be no other participants in the replicates (just what is on the primary server)... then use --disposition=ER when I clone the primary? Thanks Laurie