Found this on a VW forum.
"Hi, I just reset the service insp on my 98 Passat after trawling the internet for solutions.
The odometer is digital so i only know it works on this type.
Before resetting. It is important to remember that this reminder is displayed because your car is due for a service..!
If you have not recently had the car serviced, or have not booked it in for one, then its a good idea to leave the reminder until you are sure the car is in good working order and does not need an inspection.
Neglect the engine in particular, and it will cost you far more than the price of a service.
1: With ignition off, press the trip reset button on the right under the odometer and hold.
2: Turn ignition on. Don't start engine. Release button.
You should now see "Service Oil" displayed.
3: Press button again. You should see "Service Insp", displayed.
By pressing the button once more it displays "Service Insp" again.
4: Now press and hold the button again with right hand whilst turning the other button "for adjusting the clock", to the right with the other hand.
The display should now change to Service ----.
5: Turn off ignition.
Your Service Inspection notice should now be reset.
If this is not the case then repeat 1-5 but hold the button down once "Service Oil" is displayed.
This advice just saved me 145 Euro at the VW dealership."
Hope this is helpful.
ChicksFan, January 2010