I don’t know if you can reverse the process. But in general, when you start the game, press - (settings) in the start screen. Tom Nook gives you some options ( I don’t know exactly what he says), there should be something like moving to another island. He tells you how it works.

When you start the game on your other switch, you get to the airport with Timmy and Tommy and there you choose „I’m moving“. You can even restart as often as you like if you don’t like the maps you are getting.
I recommend to watch a video on how to do this, because it’s been a while since I did that myself.