How do you reset a service message on a 2004 Volvo s60?

To reset the service message on a 2004 Volvo S60, turn the ignition key to the "II" position without starting the engine. Press and hold the trip odometer reset button on the dashboard. While holding it, turn the ignition off and then back to the "II" position again until the message disappears. Release the button, and the service light should be reset.