This is an easy way to cool your Xbox
Step 1: How to Start
take apart your Xbox, be careful and make sure it is unplugged as you will expose high voltage components., then find a box that will hold the parts, see above.
Step 2: How to Install
find a box that will fit the peices and tape the HDD in by rolling up tape and putting it under so it acts like double stick, or use actual double stick, then use wire to tie the circuit boards to the box, feel free to do what you want to hold it together make it yours
Step 3: Adding Fans
take any fans you have and put them in places where overheating is possible, then put a breadboard circuit board in place that is reachable and wire the fans, I wired the fans all in series so they not overheat, however I put the larger fan in parallel so it could get the required volts, how to wire will carry based on your fans and power supplie
to reach the buttons I just cut holes in the side and wired pieces to the cardboard so I could get to them without having to disturb other pieces. this should cover all you need to do, if you want you can add lights and stuff, really whatever you want.