@Bobby_Wilson, I was in the same boat as you. I had soldered some things 35 years ago when I was a kid working on model railroads, but I hadn’t touched a soldering iron since. Here is what I did:
This is the Genie remote I used:
I programmed the front button to open and close the desired door. I then used a coin to pry open the remote as if you were changing the battery.
Here is the finished soldering job:
You will see that each of the three buttons on the remote have two contacts, right and left that need to be “Closed” for the button to activate. Before soldering I used the multimeter and tested for continuity to find that the top half of those circles were part of the same side of the switch and the two bottom halves were part of the other side. I switched my multimeter to a voltage testing more (I think) and when I touched the top of one circle (2) with one probe and the bottom of the other circle (1) with the other probe, the LED blinked and the door opened. Voila!
Obviously the soldering was nerve racking. It could have gone badly very quickly. If the solder crossed from the top half of the circle to the bottom half, I would have had a closed circuit all the time and it wouldn’t work.
I hope this helps a little bit. Good luck!