Hey... to make an omelet, ya gotta break a few eggs

He'd have every right to go medieval on the bureaucracy. He can't fire most of them but he could damned sure reassign a lot of them to quiet offices with a lot less power than they had before. He'd be a fool to neglect getting rid of the insurgents around him that will be trying their best to shank him at every turn.
Add to that the fact that your media 5th column has lost the trust of all but the most insane Leftist partisans and the likelihood that one or both houses of the Congress will be in opposition this time and if you're a Lefty, things won't be lookin' too spritely for the home team.
Uh huh. Leaving out that part where the scum you support in DC FOUGHT HIM EVERY STEP OF THE WAY... aren't ya, Cletus? They were so brazen with their moves that every one of them was eventually overturned by a much less amenable SCOTUS in 2017-18.