REAR SEAT BELT RETRACTOR PROBLEM

[RoGrrr]

I have a 93 325iS in which the rear seat belt retractor is stuck/locked.
Not a problem, being one of those inertia types. I’d just unbolt the lower attachment and allow it to reset.
As I let it retract, I heard a ratchet sound, which I was unaccustomed to, so I tried to pull it out. LOCKED. Let in some more but still locked. All the way in, until I could not pull anything out.
Seemingly, not a problem, I’d just remove the seat back and figger out what’s wrong and repair that.
Only thing is that I can’t figure out how to get the seat back off. I’ve done most everything without damaging the backing panel and still am at a loss.

Anyone have solutions for me ?