1994 Geo Prizm seatbelt release?

My kids twist the rear seatbelt, and it gets stuck. I usually am able to go in the trunk and remove the one retaining bolt and pull enough seatbelt in to release the child restraint feature and release the belt. This time the child release feature stayed stuck so the belt is all the way in now, but won't release and come out. There's gotta be a release mechanism somewhere in the gearing that I can release it? Everything looks riveted into place and self contained though, and I can't see anything easy to get to.