Hold MENU, and select Settings > Sensors & Accessories > Compass.

Calibrate

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

Display

Sets the directional heading on the compass to degrees or milliradians.

North Ref.

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

Mode

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