It is called torque lock, you have to push the car forvard with some help or other car, or just rock it back and forth, some cars have the button under small cover near the gear shifter, you push it and is it unlocks the gears. It is the same as the parking brake with up hill position of the car. You can't just press the button and relise it, you have to pull it a beat more and then you can pres the relise button.