I followed the "less messy technique" today of "Mthomas" in post 43 here, minus messing with the serpentine belt and it worked great. I have an 06 330i as well. A few notes:
1. I used a turkey baster to draw fluid out of the reservoir before undoing the banjo bolt (this minimizes the mess under the car).
2. I put Al foil over the rubber accordian-type cover on the steering rack that is directly below the banjo bolt to keep it from getting dirty (see picture). I also crafted an Al foil funnel to feed all fluid to my catch pan.
3. I took off the airbox to facilitate top access to the banjo bolt (which is actually decent, better than from below in my opinion).
See the e90 N52 Airbox Removal DIY HERE. After removing the airbox, I covered the open air inlet so as to not contaminate the engine.
4. I replaced the aluminum crush washers at a wopping $0.67/ea at the dealership. Worth the peace of mind.
5. When draining the fluid via turning the wheel, I advise you have your drivers door open and turn the wheel as you watch the fluid drain under the car. I was able to monitor it actively so I knew when to stop. I turned it back and forth ~5-10 times, going fairly slowly.
6. I was able to refill ~90-95% of the 1L of pentosin CHF-11s, so this procedure is pretty good at getting lots of fluid out.
7. Per the torque spec (26 ftlb), I have a rather long torque wrench and there's no feasible way to get a torque wrench like mine in there. I decided to just tighten it by feel, and not like an "ape" as others have referenced. Seems fine to me.
8. My 06 330i has 51k miles and quite frankly, the fluid still looked pretty good (still green colored, not dark/black like others have shown). Peace of mind I guess.
9. When doing this, its a good time to replace your coolant if you haven't already. Just make sure the car is level when doing the coolant (mine is currently still up on 4 jack stands).
Below is the aluminum foil mock-up I created to minimize the mess on my car. I didn't want the fluid dripping on the rubber around the steering rack, possibly degrading it over time.
