hey all - i purchased a replacement steering angle sensor and tried to install last weekend...couldn't figure it out. Bentley manual arrived yesterday... still can't figure it out.

there looks to be one simple black bolt on the u-joint between the upper and lower steering column. I think i'm supposed to remove that bolt, but i have no idea what to do next. anyone done this and can provide some advice?

 

First, make sure the steering wheel is point straight ahead. Rock it back and forth with the key removed so that the lock engages and the wheel can't be turned anymore. This will prevent the clock spring from over or under winding while you have everything apart.
From underneath the car (up on jack stands) unbolt the u-joint from the steering rack.
Next, unbolt the u-joint inside the car in the footwell. The lower half the steering column should pull right out and you now can remove the angle sensor.
The new sensor will need to be calibrated with a BMW/MINI specific diagnostic tool. If you don't have this, then you'll need to bring it to the dealer or a capable indy shop.