Check Ross-tech:
http://wiki.ross-tech.com/wiki/index.php/VW_Golf_(1K)_Steering_Assist#AdaptationQuoted from above link pretty sure it's:
Start the vehicle.
Turn the steering wheel one turn to the right and one turn to the left.
Drive in a short distance straight line on a level surface at a speed not higher than 20 km/h.
If the steering wheel is straight during the test drive then stop the vehicle with the wheels pointed straight.
Ensure that the steering wheel is not moved again.
Keep the engine running and do not switch off the ignition.
System voltage at leas
Also
(Engine still running)
Center steering wheel (±10°) and hold it centered for 5 seconds.
Turn steering wheel completely to the left and hold it there for 10 seconds.
Turn steering wheel completely to the right and hold it there for 10 seconds.
Center steering wheel (±10°).
Switch OFF engine and ignition.
Switch ON ignition.
Wait 5 seconds.
Steering Assist Warning Lamp should turn OFF. If it doesn't, perform a short test drive.