Its really easy. You want to be sure to do it with the slide back, otherwise the safety lock will fall out (PITA) and be careful as there's a little spring and ball bearing right under the switch shim plate. They say you don't need to re-use the shim but I put it back in anyway. And the screw is an anti tamper screw. You just need to set your screw driver on it and give it a couple firm taps to break it loose. I tightened everything up the 1st time with the safety on and it wouldn't move. Loosened it and tightened it again with it off and it worked. There's a few videos on Youtube that explain it pretty well. I changed out the one on my 500 too, the Mossberg switch chews my thumb up.I purchased a picatini (sp) rail that I plan on mounting and putting a 206 on. How hard was the safety switch out?