Removal Procedure

Replace the batteries when the range of the transmitter decreases to less than 7 m (23 ft).
Insert a small coin between the two halves of the transmitter case at the slot provided near the key ring hole.
Twist the coin in order to open the case.
Open the transmitter case.

Fig 1: Twisting Coin In Order To Open Case
Courtesy of GENERAL MOTORS CORP.
Remove the battery (2).

Fig 2: Removing Battery
Courtesy of GENERAL MOTORS CORP.