For this mod you have to open your system and your DVD drive. To open up your system you need a torx 10 screw driver and some pliers. I will not cover this step, as I never had to do it. My xbox 360 was in terrible condition and the case was already destroyed. So I never had to go through the tedious task of open it. To do that I recommend watching this video.
Some people have trouble getting the video to load, so click here
if you're having trouble.
But if you already have your xbox open the only thing you need is a regular Philips screw driver, super glue, and some foam. The type of foam doesn't really matter more of the size. I can't really specify the exact size of foam you would need for this as it was mostly trial and error for me. So get some foam that is about half an inch thick so you can cut it down to perfect size. If you are going to be buying foam for this project I recommend buying 8x11 craft foam. The first time I did this I used to Styrofoam and it worked fine, but it didn't stay to together as well. The 2nd time with the craft foam it worked perfectly.
By the way I originally got this idea from llama's 360 adventures. Except they don't really tell you anything and just try to sell stuff.