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
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.
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.