It should be noted that the "star" rotation to loosen it depends on which side of the car you're on. If these aren't loosened properly there's going to be serious issues getting the old rotor off.
It would also be an excellent time to wire brush the hub/bearing before mating the new rotor or any corrosion on the surfaces will result in the rotor not mating properly and wobbling, thus making the whole wheel assembly wobble. A very thin coat of anti seize (not enough to fling off into the p-brake) would also be a good idea. Some anti-seize where the wheels mate too will make sure that wheels never get overly attached. These are issues particularly in salty regions.
The opposing star wheel adjustments, along with the rest of the standard BMW p-brake adjustment procedure seems to be fairly well documented here:
http://www.csfrancis.net/BMW/pbdiy.pdf
Note there are adjustments at the p-brake handle as well.