How can I pair my old Apple Watch 3 with my new iPhone.

How can I pair my old Apple Watch 3 with my new iPhone. When I go to pair from my new phone, the phone hangs up on the updating software screen and will not move past it!!

I have tried resetting the watch again and go to the manual pair on phone, but it will just go to to updating software screen, with the watch stuck in the pairing screen.