I took the rear sight off my M&P when I had it using B & J Machine sight pusher http://www.brownells.com/gunsmith-to...prod54823.aspx to get to the striker block with no problem. I've taken off quite a few friction fit front and rear sights that have/don't have a set screw from many brands of guns and I can buy sights straight from the factory as well.

Most of the time, my simple delrin punch will do for rear sight removal. http://www.brownells.com/gunsmith-to...h-prod512.aspx I know people are looking to replace the plastic rear VE sight for an M&P one like on the SD9/40, so I'm not sure why after market sights making for a better shot was mentioned.