I recommend following 66FSTBCK's write up he posted the link to. Take note of where he said he had to remove a few tie wraps to spread things out. I found this necessary about 1 foot from the block where the leg for the headlight switch, rear harness and accessory harness split off. Those 3 together go around the back side of the air vent can. Protect that group with either spiral wrap, snake skin or corrugated wire loom as the wires can rub or get tangled in the actuator arm of the air vent.
Also in this grouping is the dome light, or courtesy lights. It goes to the drivers door first, then across the dash to the passenger side.
AAW could have done a better job of demonstrating the routing techniques behind the dash, other than the drawing they provided.
Putting the harness in first might not be possible due to the routing around the air can, and I wouldn't do any welding around the pinch with a harness up in there. Although, it is away from it, just wouldn't take a chance on a new $600 harness.
I regret not spending enough time wrapping more before the install. Even thought about pulling it all out and starting over. Seeing how the funds are gone, I might just do that since I have more time than money these days!
1966 GT Fastback, restoration almost there! Code T Red with White LeMans stripes.
2015 GT Fastback - Deep Impact Blue