Replication - Upgrating SEPM 12.1.5 to 12.1.6 MP4

What actions I should do with the replication, before that I upgrade the SEPM since v12.1.5 to 12.1.6 MP4 version. I have to servers that use the same site.

Should I only stop the  SEPM service, or  do need I to do something more. I read that some case the replication should be stop.... I need help. 

Can you give information about this?

Thanks for your help.