Take apart the existing garage door opener and solder two wires to the Button. This Mod should work with any Garage door no matter what brand since you're using the Opener that came with the system

Here you can see the two wires more closely. I used duct tape on the back to keep the board from touching anything metal. Some people put the case back on and then drill a small hole for the wires. To save space I left it off.

NOTE: The best way to find out where to solder is to take a paperclip, bend it U-shaped and touch the two connecters that will open your door. Once you find the two connecters that is where you solder the wires. It's usually behind the button on the opener.

I used a Targa Roof Switch (996 613 119 10 A05) which you can purchase from any dealer.

Just follow the wiring in pictures. You can see I joinded the 2 wires connected to the top plug.

NOTE: If you want the switch to light up like your other switches, move the plug on the left to the bottom center one. Run 2 wires from the side slots to the same side slots on the Power Window Switches. I made this change, but have yet to take pictures.

Just another view of the Wiring.

AGAIN: If you want the switch to light up with your other switches, move the plug on the left to the bottom center one. Run 2 wires from the side slots to the same side slots on the Power Window Switches. I made this change, but have yet to take pictures.

Top view of the switch...

NOTE: This was the old switch I used before the Targa Roof Switch.

Connecting the Targa Switch to your Garage Door... Simple as 1,2,3. Please look carefully at the wiring. Notice 2 of the wires are joined at the end to form one plug.

Another view of the wiring...

Everything put under the ashtray and switch in place.