OK here's how to do a 12v mod, but it's extremely loud. You will also lose the auto-adjusting functionality of the fans, where the voltage increases as the CPU temp does. That shouldn't be a problem though.
STEP ONE:Take the
RED and the
BROWN wires shows below, and cut them off at the top of the plug, so you have the most wire left. Leave the BLACK and
BLUE wires, as they're just grounds.
STEP TWO:Twist, then solder the
RED and
BROWN wires together, then solder a third wire to that, about 5" long. Solder the OTHER end of the third wire to the pin shown below, either on the bottom of the motherboard, or onto the wire that does to the DVD drive.

And there ya go, both fans are now running at 12v. If you only want 1 fan to run at 12v, cut only one of the wires,
RED or
BROWN, and leave the other one alone. If you want 1 or both of the fans to run at 7v, then cut the BLACK and
BLUE wires, and solder them to a 5v source on one of the USB plugs.