PO really mucked up the wiring on this truck. Wires are starting to come loose (wound together and taped, no connectors, no solder, nothing...)

I lost my headlights the other night, and the rest of the wiring looks just as bad, so I'm going to work over leave with a soldering iron and some shrink tube to make things better. I can't get access to a lot of the areas without pulling the whole dash assembly off (not just the gauge bezel surround). I got it all disconnected, but its connected to the heat ducts also. How do I disconnect those, I'm searcing all over and can't find the screws.

Any help is appreciated at this point.
Thanks