hi Shrinivas,
There is a rename function for documents in the AutoPLANT Relationship Manager, however it has been historically buggy. In the past, I have simply copied the DWG, deleted it from either document manager or relationship manager, renamed the copy, then re-imported the document using relationship manager.
Worst case scenario you have to reconnect your equipment nozzles to your piping. The rename function may work now, but I haven't tried it in recent versions.
