Upon impeaching the President, the VP would become President, and he would order the military to remove the ex-President. At that point the military would have to decide if it's more loyal to Congress or the ex-President.
Because they could just as easily impeach him if he doesn't, then it falls to the Speaker of the House. But if I were them I would just impeach them both at the same time for the same reasons.
And who impeaches a President which just gave himself the right to authoritatively misinterpret the law in whatever way they want and in turn can trivially turn you live into a living hell if they insist too
especially if you yourself could get a part of the pie and don't think it will negatively affect you
I mean don't get me wrong if they would do so literally tomorrow it would work.
But as the majority of senate likely feel they have little to loose it won't be tomorrow.
And when they realize that maybe they won't get part of the pie (they are mostly now useless for him) it will be to late and the fear of repercussions will have set in.