How do you program the universal garage door opener for a 2002 Mercury Mountaineer?

If its a HomeLink, do this: If its new, or there's no codes of value, hold the 1st and 3rd button down at the same time for a little over 30 seconds. The light should blink real fast. This wipes out the memory (needs to be done when its new). If you don't want to wipe out the memory, then just press and hold the button you want to program. Also, press and hold the button to the garage door opener right next to it. Hold them both down for a few seconds until the light blinks quickly If THAT doesn't work, then your garage door has a "rolling code". The manual will explain, but you'll need to take the cover off your garage door and press a button on the motor, then follow some steps inside your car.

hold the button down on your car remote, then push the button on the garage door remote. it should copy the code.

a grage door remote