Solder by touching your soldering iron tip to the pad to heat it up then apply solder to the hole in the pad and the solder will wick into the hole and make a good electrical connection. When complete, your work should look like the picture below.
We have not been able to buy the original switches we used in the first kitting. Some kits will be shipped with switches that have a shorter lead length. They are still easy to install if you follow these suggestions.
You may have to bend/adjust the leads to get the switch to fit in the PC board. Since the leads are not long enough to go all the way through the board, we can't bend the leads over to hold them in place. Instead, tape the switch in place with a piece of tape on top of the board.