Legally, there are a couple challenges to be made to his eligibility that will likely be brought by some states. The main one that comes to mind is If there is a case for insurrection then the 14th amendment applies.
Another potential is the 25th amendment. This would require J.D. Vance to get half of the cabinet on board to remove Trump from power. I'm wondering if this is something that is already in the works considering J.D. Vance's true feelings for Trump that were revealed in the past. It's probably a long shot, but who knows.
I would imagine (if they’re savvy, and the people running Project 2025 definitely are) they’d be more likely to keep him around as long as he was a useful distraction, then have him assassinated at a key point, and blame a liberal.
That would not only get him out of the way so the real work could begin, it would do double-duty of riling up his murderous base and giving them a ‘legitimate’ excuse to start sending the military after blue states and political rivals.