What he does in those 79 lame duck days is somewhat limited by Amendment 25. For instance, if he tried to launch nukes at somebody I think Pence would cooperate in Amendment 25. It would do wonders for Pence's reputation, which is pretty much in the toilet now.

I think it would consist of Trump being carted of by ambulance to some nice rubber room, for a "mental breakdown". They'd drug him up and render him incommunicado while they do the paperwork.

I also read something about Pence being willing to do it after some Trump outrage in the past. That has the advantage for Trump of giving Pence some time as President so he can pardon Trump of his federal crimes. Happened with Nixon!