Front is quite simple. Just drop the reinforcement plate and the bushings and you are done. The rears... don't do it. You don't want to mess with factory aligned suspension subframe just for a sway bar...
If you really want to do it, make sure a good, certified body shop aligns the subframe for you.
E92 M3 DCT - AiM EVO4 Data Logger / AiM SmartyCam HD / KW Competition 2-Way / OMP ARS Racing Seats / Brembo GT 365 / Pagid Yellow RS-29 / Rear Seats Delete