My 96 Camaro had a feature that would let you cinch up the seat belt for high performance driving such as autocross. The sliding plastic part which makes this work, broke on my seat belt. I have another buckle that I found in a wrecking yard. There seems to be a small metal clip inside the buckle, holding the plastic sleeve in place. Does anyone know how to get this apart.

 

I don't know about disassembly, but I accomplish the same thing in my '02 using a product called CG-Lock.