u The reset is in your menu that you can scroll through with the directional buttons on the left side of your steering wheel. As far as I know the compass button is just to bring you out of your menu and back to the main display.I've got the optional 420 NAV unit. There is no reset button on the steering wheel.
There is a compass button, but it does nothing. Strange. The compass display was there when we picked it up and was there for about the first week. Not it's just 2 short lines to the left of the outside temperature display.