The process is very similar (with some simplifications) to regular 3 Series' install:
http://www.e90post.com/forums/showthread.php?t=15397
All the bolts and nuts that need to be removed are circled in red. BMW recommends
replacing all nuts and bolts.
Torque specs:
http://www.m3post.com/forums/showthread.php?t=183005
I've done this so many times since when this thread was written. Now updated for 2010
Best Practices:
Front Axle:
1. When removing the front springs: use a jack and push up the front suspension to compress the spring, and then put on the spring compressor. This will save you a lot of time.
2. The strut piston rod can be pushed into the shock with hands.
Rear Axle:
1. When
loosening the bolts: loosen the shock bolt
first, the camber arm/wheel carrier bolt
second.
2. When
tightening the bolts: tighten the camber arm/wheel carrier bolt
first, the shock bolt
second.
3. It may be very tough to align the wheel carrier with the camber arm. Try jacking up the camber arm, and use a wrench as a level to position the parts.
4. When aligned correctly, you should be able to push the outer bolt completely through the camber arm, without any turning. This bolt is tightened by the nut.