wiring harness issue please help

[emmveekay]

I feel like I'm about to lose it, searched multiple forums to no avail, any advice appreciated.

my wiring harness is f'd. I bought a new maxima and it wasn't at all what they said it was. Long story short, the back of the motor caught fire and the damage looks minor, just the wiring harness and power steering hose. I called Nissan and they quoted me over $1000 for a new harness.

My buddy basically told me to just find the where the good wire starts, cut and solder new wire to replace the burned/damage wire. For the life of me, I've got the whole harness unplugged but can't get it through the firewall, don't know how what else to unplug from the firewall back due to the dash, or if there's anything securing the wiring to the firewall from the inside due to the evap box. Are there any write-ups on how to remove it or does anyone know how to remove the wiring harness on a 2003 Maxima?

Thanks!

[emmveekay]

*can't figure out how to pull the rest of the wiring from the cabin through the firewall into the engine compartment