How do you switch service light on hilti dd200?

The service light comes on after a certain numbers of hours. I think around 200 hours. The indicator light lets you know you have just a few hours before the machine shuts off and has to be serviced. I think on the DD200 it is wired to the carbon brushes. Once they wear down to a certain point the light comes on. After that they wear down further until a pin pops out cutting power to the motor.