How do you install a 1966 mustang wiring harness?

To install a 1966 Mustang wiring harness, start by disconnecting the battery and removing the old harness. Carefully label and document the connections for easier installation. Install the new harness by routing it through the appropriate areas, connecting it to the ignition, lights, and other components according to the wiring diagram. Finally, double-check all connections before reconnecting the battery and testing the system.