Odd problem

Reinstalling the drop for my t-case(went up another inch and HAD to see if raising it would cancel the vibes until I can get ahold of an SYE) my impact wrench spun one of the welded-in nuts in the frame that the crossmember bolts to. The bolt is in now, but not tight. I think I can get it out, but what then? Short of drilling a pilot hole in the unibody and spot welding it back, is there anything I can do? Appreciate the help.

Only thing might be to put in another nutcert once you get the bolt out. The tool for doing that sized nutcert is pretty heavy duty and the only one I have seen is at the dealer.
The only other thing I can think of is to cut some 1/2" thick stock 2" long and as wide as the frame rail, drill it, tap it and somehow fish it in there. An outside solution might be to weld up a U shaped deal, drill and tap the bottom and then bolt it thru the frame rail with self tappers like the rock sliders do or bolt it all the way thru both sides of each frame rail. Might need two of them though , one on each side, so the cross member is even.
Those expandable nuts may make assembly at the factory easier but are a PIA for long term ownership/mods.

I snapped one of those bolts inside the frame. What is the easiest way to get them out of there?

i don't know if it's the easiest way, but assuming the bolt just broke, I drilled and tapped 3 of the 4 holes on my old XJ.

it was a PITA, but I had to do something

First i removed the bolt ( I just broke mine off) then using an air hammer (or I guess a punch woould work too), I pushed that nut up into the frame-body, then I used heavy duty rivet style nutserts on the remaining hole.

Besure to practice installing one on a piece of steel the same thickness as the metal making up that hole so that you are sure that it crushes to your liking.

I have slammed my crossmember on everything and run 75 mph all day, it is still tight!!!