How do you reprogram a 1998 Cadillac STS garage door opener?

To reprogram the garage door opener for a 1998 Cadillac STS, first, ensure the vehicle is in park and the ignition is on. Press and hold the two outer buttons on the home link system until the indicator light begins to flash rapidly, then release the buttons. Next, press the button on your garage door remote while simultaneously pressing the desired HomeLink button until the light flashes again. Finally, test the programmed button to ensure it operates the garage door.