Ahhhh! Wires...

So my mag swap is still underway,
The plan is swap a lot of the Ram into the Dart;
Heater box, wire harness, steering column, gauges and various other components.
So the most time consuming part is pulling the wiring harness-sheesh what a job.
I'm labeling every plug (orange tags), wire, box I remove and haven't cut a single wire, but Murphy's damn law, I've got 1 unknown plug;
Passenger side by the kick panel and heater box I'm going to have to chase...
Here's a pic so far;

Pics deceiving, the pile of interior wiring is about 2ft tall!
1 question though;
I'm ready to pull the engine bay wiring into the cab to remove thè harness or the interior into the engine bay, but with all the boxes they won't fit either way thru the firewall hole, for you guys that pulled the wire harness, how did you get it out?
Unplug all the boxes?
I thought about cutting the firewall with my recip saw to ease removal(?)