I just installed a set of XS Big dots on my 9mm Shield. I used a steel punch to remove the stock ones. They weren't destroyed, but marred on the left side in the process.Didn't damage the slide at all. Had to whack them pretty good. XS went in much easier, the rear slid right in and tightens with set screw and for the front follow the instructions exactly (keep filing the base until it slides in half way,load up with included loctite, then use included plastic punch to knock it into place).

The sights are rock solid. Haven't shot with it yet but the install wasn't bad and I don't have any special tools. Only things I grabbed from the toolbox were a standard steel file, hammer, and a nail punch.