Originally Posted by ncx

Hook up 12vdc to the starter. Take a spare battery or battery charger - connect positive to the front + terminal on the starter, then connect negative to bare metal on the frame. Use highly conductive cables. Now that you have electrified the system use your remote to unlock the car. This works for completely dead batteries so should work even though your battery is physically disconnected. The starter is on the rear of the motor on the passenger side and accessible from the bottom.