My Trooper (3.1 duty) has just had a new timing belt fitted following a failure which caused some valve and cam damage. My local garage has fixed all that and all is working well

The light on the dashboard (which had come on about a week before the failure) is still on. I seem to remember that this is an automatic light that comes on every 60,000 miles and that there is a reset button to swith it off

They do not know where this is

Can you assist?