Hold MENU, and select Settings > Sensors > Compass.

Display

Sets the directional heading on the compass to degrees or milli-radians.

North Ref.

Sets the north reference of the compass (Setting the North Reference).

Mode

Sets the compass to use either a combination of GPS and the electronic sensor data when moving (Auto) or GPS data only (Off).

Calibrate

Allows you to manually calibrate the compass sensor (Calibrating the Compass).