It's under the hood on the outside of the firewall. You remove nothing. It's just there out in the open. Runs from the vacuum tree in the drivers corner, over to the other side about where the heater core lines are. Then runs through the firewall. MOST of the time it breaks in the engine compartment. But on occasion some have found the break, up in the dash. That's no fun, but can be found if you pull the stereo and center piece out.