Yeah, they do come apart. I've had a couple bolt snaps come off, and have seen them come off on a few other divers. You should redo them when they start to look ratty.
I thought that this forum was for DIR answers only Rick?
From here:
http://www.gue.com/Equipment/Config/index.html
Two back-up lights are
attached to each of the two chest D-rings, one light per side. Each is held to the strap by an elastic band. This puts them beneath a diver's shoulders, where they are completely accessible but out of the way. Divers can always reach these lights and turn them on without unclipping them from their D-rings. Turning on a back-up light before unclipping it is very important; divers could easily drop their back-up light while trying to get it unclipped before turning it on.
Mark