Early 90s GM seat belt retractor, fixing or replacing?

1992 Caprice. I'm considering making an offer on the car.

 3/4 shoulder belts are pulled out and won't retract. How big a deal is this to  remedy and is it a repair or replace? (Suprisingly) not something I've dealt with before and wondering if someone here has any quick advice.

Gotta be a common thing.

 I've done some quick YouTube searching and mostly found videos of people working on newer stuff.

Are they pulled all the way out and stuck, or partially out and do not fully retract?

If partially retracted, will they pull out further?

Pulled out all the way (I think) and won't retract.