If you don't want to or can't DIY the job, just go to an indy shop.
I had to get mine replaced on my old 530i a while back and didn't have the time to do it myself. I paid $380 total with labor for OEM rotors and pads + labor.
Luckily the dealer replaced the rotors and brakes just before I bought my e90 so I won't have to do that again for a good while.
2010 Alpine White 335i
- Sports Package, Premium Package, Navigation, Comfort Access