Simply lever the bolt back, so you can see the side of it. No disassembly at all. On the left side of the bolt, you'll see a small pin just below the safety. Tap it out, left to right. Lift out the safety, dispose of in garbage, place plug, and reinsert the pin, right to left. Pay attention to the notch in the plug, so the pin will mate with it. I did have to do a very tiny bit of sanding on the plug shaft to get it all the way in. Total time if you don't have to sand, about 5 minutes. It's that easy. Mine with sanding took all of 10 minutes. I forget, but there may be some brief instructions with the plug.