Before replacing the gateway, get out your VCDS or OBDeleven and note the coding and installation list.
Remove the kick panel at the top of the driver's footwell - undo the two T20 screws and pull the front down. Stick your head down there, and looking up, towards the centre of the car there will be a red plug. That's plugged into the gateway. The gateway is held in place with those two press lugs. Push it out, unplug it, plug the new gateway in, then use your VCDS or OBDeleven to set the coding and installation list correctly. Once everything's working correctly, push the new gateway into position, slot the far end of the kick panel into the retaining lugs, push it up into place and do the screws back up.
