There is a rubber boot that comes out into the engine bay on the passenger side underneath the glove box. You can just push the wire through with the help of a rod or tool. Just be careful not to hit the wires. I pushed my power cables through the side of the boot and used a long pair of pliers to pull them up to the battery. (its a long reach!) I fit a 4ga and an 8ga wire through there so there is plenty of space.
