I can tell you from personal experience that you must, I repeat must be careful when putting the new stock on as they use different lengths of bolts. I put a stock on my 686 that came off another 686 and the bolt screwed into the trigger assembly. It was not good. I used a 12 inch 1/4 inch extension and 6 mm hex socket. Nothing to getting the stock off. As mentioned above, hang on to the receiver. I would recommend putting the receiver into a vise and then you can gently pull the stock loose as you unscrew the stock bolt. Jackie B.