2002 mustang gt seatbelt wont retract or come out

Alright, as the post said, the seatbelt needs help. I'm tryin to help a friend out its not my car. I am rather handy, and wanted to fix it for him, never messed with a seatbelt b4. It is the passenger front belt I believe. I am assuming that the belt is most likely twisted inside the mechanism, and wanted to know how to get to it. Having not looked at it yet myself, I dont know, but is it something that the hole mechanism would need to be replaced, or should it be a matter of taking it apart and fixing a bent spring or something. Any thoughts would be much appreciated. My firebird interior and everything on that came apart easy enough, never messed with the ford rival, looking forward to it.:screwy: