How is this mount installed onto an M&P? Does it require special tools?
Anybody ? 
The slide has to be machined.
Are you talking about the Trijicon mount that replaces the rear sights? If so, it will need to be fitted to get in (typically). Not really a big deal.
We sell the mounts, RMR’s and can do the installations on your slide.
https://www.m4carbine.net/showthread.php?t=80237&highlight=rmr
C4