Service Reminder Light Reset

We have a 1998 volvo S90. How do you reset the service reminder light?
Volvo says it is a manual procedure, no electronic equipment needed.

We have tried a number of times with the odometer button and ignition key position but that doesn't work.
Thanks
robert
:banghead:

start with the key in position 1 hold down the odometer button in trip 1 while holding the break down switch to position 2. let off the brake and keep holding the trip button untill the triangle with ! in the center blinks 4 times then let go.