Step 1: Materials
Next, you'll need some 5 mm red LEDs. I got mine from circuit specialists in Mesa, AZ - $1.64 for a bag of 100. Don't get them at radio shack. You'll need at least 24. Any number divisible by eight should be fine.
Also get some hook-up wire, alligator clips, and a potentiometer.
For tools, you'll need an electric drill or a screwdriver and lots of patience.