How to modify a shuttle PSU for my custom 17" lappy cooler

[shuRe]

I have taken the size of the psu into account for my 17" laptop cooler, but am unsure of how i will turn this thing on. IT will power a fan controller and 3 fans. Usually PSU's are turned through the motherboard, but seeing as i havnt got one does anyone know how i could modify it to turn on when i switch the on/off button at the back 'on', or another way?

Thanks

[wr0x2]

http://www.7volts.com/atxnotes.htm

There ya go.