I too replaced my whole axle assy (front right) with an aftermarket and have had any issues, has driven smoothly for a while now. I paid $87 for mine. You really shouldn't need any special BMW tool or even a 3 jaw puller. Since you are replacing the entire axle shaft assy as I did, all you need to do is get you a nice beefy punch and a beefier sledge. Center the punch on the axle indention and give it a few nice solid pops. The shaft will begin to move inward. A few more light taps later I was able to pull it inward out of the hub with just my hands. There is enough play at the u-joints and if you have unbolted the rear of the control arm for it to slide out. I wasn't worried about the damaging the axle because it was being replaced. I have a 3 jaw puller and originally got prepared to use it but I really did not want to dislodge the dust cap so after looking at it for a while I decided to use the sledge/punch method. Came apart easy as pie. I did use never-seize on the reinstall so that it would be easy to take apart on the next go round. Not a very difficult job but it can get a bit messy depending on the condition of your old boots. Good luck with it!

__________________
2010 Lexus RX350 still new
2003 BMW X5 3.0i w/sport package w/68K miles. (gone Thank God!)
2002 Dodge Ram 2500 4X4 cummins diesel w/198K miles, custom repo truck
2009 Scion tC w/46K miles
2007 Suzuki SV650 custom streetfighter
2000 Lexus GS400 w/165K miles