Well its not quite THAT easy. I popped the headliner down but its not completely off, I've got enough room to see the nut and slide my hand in there to feel it and yea that sucker is big. I don't have any small wrenches that will fit around that and turn. The adjustable wrench I have is too long and doesn't really work.
Is there anyway to pull the headliner completely down, or at least more than a few inches?

I already unvelcroed (sp?) it and popped the tabs out. Right now it is being held in by the liner on the C pillars.

 

That's as much room as you get unless you take the whole thing out (including the pillars). If you can get a wrench on it, that nut just needs to be loosened and will spin easily after that.

 

Just get a smaller adjustable wrench, it really is quite simple.

 

We have a different definition of "simple". After doing it once, it's not too hard. But it is tricky if you've never done it before.