Thank you for the suggestion. 

My server computer is now his server. so nothing changed there and there is no backup to move (I do back up).  As one option, I asked the ProSeries Expert located in the Philippines how to change the prior year programs to the new owner's account but he did not understand my need and I had some trouble understanding him.  The new owner is licensed for 2024 returns.

I seems to me that ProSeries allows a new user to obtain and use prior year programs so I could just substitute names & account numbers on the prior years.