The airworthiness certificate is permanent. The registration can be changed at any time. I have an airplane where we changed the registration. Not a big deal.

Just submit an application for a new registration. Pick an N-number and use the FAA web site to see if it is available and reserve it.

Hopefully your N-numbers are stick on and will peel off to allow the new number to be installed.

Best of luck,

Wes
N78041