Standard Procedure - Erasing Transmitter Codes
WARNING: This page is about a different car, the 2004 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
To erase the universal transmitter codes, simply hold down the two outside buttons (1 and 3) for twenty seconds.
NOTE:
individual channels cannot be erased. Erasing the transmitter codes will erase ALL programmed codes.