I'm finally getting around to swapping in the sunroof assembly I got at the junkyard a few months ago. I cannot recall how to undo the plastic cover that is over the ends of the oh sh!t handle (officially, the "assist grip"). There are two varieties. One is really easy (there are little covers that have a slot that accepts a small screwdriver and you just pop them open to access the screw).
The other variety is where the handle goes into a cover that must be snapped over the entire end of the handle. It basically looks very similar to this WRX handle image I found:
When I was taking out the sunroof from the donor car, I remember thinking, "D@mn, those handle covers are tricky, I should remember how to do that later so I don't screw up my car."
Of course, I cannot remember the trick to pop them off.