All you need is a 5v cooling fan. Screw it to the heatsink. Make sure the fan blows at the heatsink not just to help air flow. I found this fan from an broken laptop. It's a 5 volt cpu cooling fan.
Connecting the fan to the xbox 360 is very easy. You will find a 5 volt source right under the heatsink. You can connect to any part of the case for grounding. I chose to use the top of the port where you plug in the power button borad instead of a spot on the case. That way the fan can stay on when you take out the board. Most computer cooling fan have 3 wires, Black, Red, and Yellow. Just connect the black wire to the ground and the red to the power source. The yellow cable is not used in the case.
