Take out the screws that hold the trunk lock cylinder in place. Some units may need you to remove the manufacturer's bolts or rivets, too. To drill out rivets, use a 1/8-inch drill and watch your drill bit closely to avoid making the hole bigger. Install a 1/8 x 5/16 inch 'pop' rivet as an appropriate replacement while installing. Take the retainer apart from the lock cylinder by lowering or moving it aside. Remove the cylinder by pulling it from the body, following these same steps when you put it back in place.