Removal Procedure

WARNING: This page is about a different car, the 2002 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.

Insert a small coin between the 2 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: Transmitter Case
Courtesy of GENERAL MOTORS CORP.
Remove the battery (2).

Fig 2: Transmitter Battery
Courtesy of GENERAL MOTORS CORP.