How do you reset maintenance service after oil change on Volvo S80?

To reset the maintenance service light on a Volvo S80 after an oil change, turn the ignition key to the "II" position without starting the engine. Press the gas pedal three times within five seconds, then turn the ignition off. When you turn the ignition back on, the maintenance light should be reset. If it remains, repeat the process to ensure it's completed correctly.