Has anyone replaced a steering angle sensor?  It's a 540, 1998, but I
can't imagine other DSC-equipped E39s being much different.  My local
BMW specialist told me it was difficult, so difficult he didn't want to
do it and told me to go to the dealer!  But I had a look and it looks
pretty simple: adjust the wheel all the way in, loosen the clamp, adjust
the wheel back out again to separate the two halves of the column, and
presumably the sensor just comes off.  Am I missing something?

The Bentley manual says a new sensor needs to be 'coded' after fitting.
 Any way to avoid taking it to (=paying) a garage for that?

Thanks.