what year? the type w/ the set screw don't have any other keeper unless some PO added something, which you should be able to see - should be able to pry under both sides at once and get it, just be careful of bending the panel behind it
try rolling the window all the way up and see if the crank can be forced [gently] further, then go all the way down and repeat - if the gnurling in the handle or on the shaft is messed up it's prolly just snagged and you might get it to shift a bit and loosen
Bill
