DIY GUYS: This fix is time-consuming and expensive! The tool to remove and press the bearings is around $250 itself. The bearings are around $30 each. If you have a while (and the patience!!) to do this job, this is your best option. You can do both bearings on the rear axle for the price of what most garages charge for one. Expect hang-ups if your car has not had much service in the rear. Frozen bolts, hubs and rotors all slow progress and are a general pain. Once you get it done, however, your car will sound like new again. The tool and parts are available at Pelican Parts (they have the best prices on this job, believe you me!).
You will need:
2 RWBs, 2 Circlips, 2 New Rotor Screws (one-use part, don't re-use the old one!) and the bearing press. A Bentley Manual is an absolute must! If you don't have one, PM me and I'll send you my write-up with alternatives, should one of the options not work.
NON-DIY GUYS: This fix is expensive! Expect the shop to charge around $300-350 (that's at independent shops). It will be a bit less on the second bearing if you're getting both done. BE AWARE that some BMW specialty shops may try and screw you. One BMW shop that I trusted quoted me at 7 hours of labour, plus over-priced parts, so watch yourself. I could've gotten the job done in 1 hour a side if I had a lift and shop tools. Seven is about what it took me in the end with socket wrenches, jack stands and a rubber mallet.