If you don't feel like reading, you can watch this video. Also, I played a little demonstration in the video.
Step 1: Materials
Small Project Box
Soldering Iron (optional)
A note about the button. I got mine at RadioShack. MAKE SURE that the button is usually open. That means that when you aren't pressing it, it's off. If on the back of the packaging the button came in it says "Usually Closed" DO NOT buy that button!