usually they can be plugged in and work without programming, however sometimes the steering angle sensor will need calibrating using computer. not doing this if needed can bring up abs faults on display. it would be ok to fit a second hand one provided it was the correct one but bear in mind this may also be faulty and contain airbag faults etc. you can do it yourself if you have correct tools. you need to remove airbag, (pops off with screwdiver through back of steering wheel through two holes), steering wheel (torx 50 socket, big bar) remove steering column surround (2x torx 20 screws) undo clamp for comm 2000 (10 mm socket) and small screwdriver to unclip wires. carefully pop out stereo controls using screwdriver. and refit it all back together.
me
September 2009