Dropping a Replication Server Definition

Use the drop parameter with sp_replication_path to remove a Replication Server as a destination from a physical replication path that is not the default primary replication path.

You cannot drop a default primary replication path and you cannot drop any primary replication path if there are objects bound to the path.
To drop RS1 as a destination, at PDS enter:
sp_replication_path 'pdb', 'drop', "RS1"
Parent topic: Creating Alternate Replication Paths for the Primary Database