As a guess; there are some actuators to control things like pedal position, the stalk itself and thats about it for parts. As for what has to be done, IIRC you have to get the systen activated via the OBD port and thats about it.

There used to be kits available on ebay, not sure if you can still get them though.
 
check that the ECU can support it before buying any kit... you will need vagcom to do it