Can't remeber for sure but I think they just clip in. You have to give it a good pull. I do not think those where bolted in. I am suprised you where able to get a used seatbelt though? Typically salavage yards will not take that type of liability if the seat belt/buckle where to fail. Personally I would never put a used seat belt in a vehicle, thats just me though, food for thought I guess
