I've gone back to the Republican Party Rules and this is what I think I see:
* Despite the fact that voting has already begun, and ballots are already printed, the Republican Party has a provision for replacing a nominee who has died, declined, "or otherwise", a suitably open-ended provision which allows Republicans to replace a candidate as unqualified and unhinged as Trump clearly is. To replace a nominee, they can call a meeting of the RNC members in as little as five days, and forego another nominating convention (this is what they've wanted all year).
* Previous case-law has already shown that Congressional candidates can be changed out after the ballot deadlines of states, though many here have argued against me on this, and they may be correct in the cases of some states.
* However, Donald Trump says he ain't quitting, and I believe him. Furthermore, Pence is already the Vice-Presidential nominee and he does not automatically assume the top-slot nomination if Trump quits....
* But Pence can trigger an emergency meeting of the RNC, by declining the nomination as Vice President. Doing so triggers the very meeting which can remove Trump against his will....
* ... And put Pence in Trump's place.
Now, two things: I consider such an event to be highly unlikely in any case, and I'm sure that Mike Pence is too damned dumb to come up with this idea on his own. He's not a "read the rules" kind of a guy.
But I'm posting it here because I'm pretty sure that the Republicans come to us for their best ideas. Heh heh heh. Look it up, Republican scum, it's right here in your rule book. It's your only chance. DO IT!
https://s3.amazonaws.com/prod-static-ngop-pbl/docs/Rules_of_the_Republican+Party_FINAL_S14090314.pdf