I would highly recommend having a gunsmith do them. I have read countless messages over the years on various forums - people who attempted to install their own sites - and then their next message shows that they screwed up their slide and/or finish on the slide.
Just pay the $20-$25 and have it done by a smith.
I just bought some Ameriglo sights from a sponsor here - Top Gun Supply. The slide is off being refinished (hard chrome), and I sent the new sights for them to install too