Ok update time. I eventually found the screw, it was on top of a big bundle of wires on the center console, below the hvac controls... ugh.
Ok so I installed it, I got it all back together, I pulled all four HVAC fuses to give it another reset, and the end result.....
No more clicking. But it also can't change from vent to floor. Its always on vent. No matter what. So thats fun. I use floor the most, so thats going to be a bummer in the winter when my feet are freezing and the best I can do is hot air in my face. But I don't think I'm going to tear this thing apart again. That was worse than doing spark plugs and V8 spark plugs are a pain in the ass.
Unless someone has a magic easy fix for this one?
I was able to reach up with no actuator and feel the gear for the door, and pretty easily move it.
I ASSUME the actuator is interfaced with the door properly but its impossible to see to confirm. But its bolted down tight which I would think would be impossible if it wasn't seated properly. I suppose the whole actuator could be oriented the wrong way, but the plug seemed to be in the right spot so I dunno.
I'm going to go look at new 4runners on the internet now.