I just purchased an m&p full-size and I'd like to keep it as a nightstand gun. With that said I was looking at some night sites with tritium. It had a warning type comment on the one I was looking at, that says the sights must be changed by a gunsmith. I've looked at the gun, and watched a couple YouTube videos. It doesn't really seem hard at all. Has anyone changed thier sights out thierself?