A new Florestone acrylic shower receptor was installed in a 2nd floor shower as part of a shower wall retiling project. The drain is 2" copper. The receptor was installed but the rubber seal that came with the receptor was for PVC so it was not installed prior to the retiling job. A Florestone Wedge Lok rubber seal for 2" copper was ordered while the tile job was completed. The new seal was installed but leaks. Turns out the 2" copper drain is NOT centered in the drain hole of the receptor. It is off by at least 1/4" or more. Shower retiling has been completed. The copper drain is fixed in its position with no access other than cutting through drywall of the ceiling below. Florestone repr says not to pour lead as a drain. Suggestions?

Turns out the 2" copper drain is NOT centered in the drain hole of the receptor. It is off by at least 1/4" or more.
If the raiser's cocked or off center then the ceiling must be opened and the raiser positioned correctly. If it's the plumbers fault then the expense should be ion him. Good luck, Tom

Where does the plumber adjust the raiser position? Does he shift the trap itself?

If he uses PVC in the repair, where would he cut out the copper and how would he join the new PVC to the existing 2" copper waste pipe?

Where does the plumber adjust the raiser position? Does he shift the trap itself?
Yes, The trap and raiser must line up with the drain.

If he uses PVC in the repair, where would he cut out the copper and how would he join the new PVC to the existing 2" copper waste pipe?
If he wishes to convert to PVC then he must cut the trap and raiser out back to the bald end of the copper pipe and convert to PVC using a Fernco Shielded Coupling,(see image). Good luck, Tom

Thanks Tom. I appreciated the picture too.