look here, try this...
1. Remove the power cable from power supply
2. Open case, remove the power connector P1 on the motherboard (if it is an ATX form factor) or P8 and P9.
3. Unscrew the 4 mount screws from the power supply, slide out power supply.
4. Unscrew the 4 Power supply screws, open box...This just killed the warrantee
5. Unscrew the fan support screws (4 each). Follow the leads (wires) to the connection on the circuit board. If it is soldered, un-solder, if it is plugged, unplug, remove fan.
6. Instalation is the opposite procedure
You can do this!