It's been a while since I replaced one on an E46 so I don't remember any tricks or problems. In general, I bleed BMW slave cylinders by hand while under the car. With the slave hooked up to its hose but not installed in the trans, orient the slave so the hose fitting is up. Slowly push the pushrod in and let it extend a few dozen times. The air goes up and out the line and gravity pulls fluid down into the slave. Top off the brake fluid reservoir frequently to avoid pulling air into the line. When it feels and sounds like no more air is in the slave, bolt it in.
Last edited by teamdfl; 01-25-2013 at 10:23 AM.