And remember to easily view all the steps add ?ALLSTEPS in your adders bar at the end.
Step 1: Open It Up
Step 2: Get the Size of Fan
Step 3: Go Shopping
And if you don't want to have to mod the side panel don't get a fan that is thicker then the one it has
I found a fan at newegg with over 100cfm (cubic feet per minute) that it moves but it is at 56 dBa (decibel)
Step 4: New Fan Installation
Now for the wiring (i don't no how to solder so i just used wire tape)
Cut and strip old fan wires (leave like 1 in on old fan if u want to use it again)
Then cut the wire on the new fan Connect the red to red and the black to black tape with wire tape.
Screw the new fan to the heat sink.
Step 5: Close and Test
Screw the side panel back on and fit all the wiring in side.
Plug in and test
Now it should cool down a lot faster and with more air flow it will have to be cleaned from time to time.
Step 6: Other Ideas
Add a fan speed control.
Put a internal fan to move the inside air.
Cut/Drill more holes in the side panel.