All you need to do is to Find a 12V adaptor, and a Fan from a broken PC Adapter, or just a Regular Fan that is 12V. Cut the Adaptor's end wire, and the Fan's wire. Plug in your Adaptor, and try to connect the Adaptor's wires to Fan's wires, and the Fan should start. I'f it does't give air cooling, the Adaptor is not 12V or the Fan. With this Tip, you can use more than 2 Fans in your Computer, Right now, I'm using 6 Fans in my Computer with this Tip. Have fun.
To do list:
-12V PC Fan
-Cut Adaptor & PC Fan's wire, and connect each wire's
-Plug in the Adaptor