I don't replace them. I use an impact wrench to pull them down. If the splines are biting into the spacer, it's good. Reverse, I back the long bolts out to make sure the threads are clear, then re-thread them in until the bolt heads are about 3/8" inch below the bottom of the PPF and hit the heads with a mallet. That pops the captive nuts out the top. This isnt't a concours build, never will be. Never had an issue reusing them. This is the fourth time the diff has been R/R'd on this car.