Required Tools
1. Soldering Iron + Solder
2. Molex with length of wire

Open the 360, then take the motherboard apart. Take out every screw on the bottom of the 360 cage. Pull out the motherboard and flip it so you can see the bottom side of the psu conneter.

Yellow on a molex is 12v, red is 5v, and the blacks are grounds. Tin the wire (add a little solder to them), and tin the connetors as well. Solder them sideways so that when you run the molex up and around the motherboard your solder joints dont flex and break. Plus makes it easier to get it past the fan.