Re: Switching PSU fan
Take the wires from the fan, strip them, twist together. Take the wires from the plug, strip them, twist together. Twist the reds together and blacks together. Tape it up with something, preferably electrical tape, but since we're being cheap, Scotch tape or duct tape (or masking tape or whatever) work fine too.
Take the plug and fan, strip the wires, twist reds together, twist blacks together, put flux on them, solder them together, use heatshrink or electrical tape.
I used the good way to replace a PSU fan I had, but I have a soldering iron, if you don't have one and plan on fixing stuff, I'd suggest getting one (they're really cheap).