floor vent vacuum pod

[Jerry_W]

Sorting out the climate control (see sig), with a bit of patience, a changed dash and JamesDeans effort, I seem to have it...EXCEPT. The floor vent worked twice, and then quit. Vacuum leak.
I read the wikki on replacing it, but can't figure out how to disconnect the element's shaft from the bellcrank. A detailed description would be great, a picture of the set up (obviously, an assembly that is out of the car) would be really great.
I can't even see the setup on the parts car, and the dash and the console are out of it.
I can reach it, but the nerve damage in my hands prevents me from getting a good mental image from what I have my fingers on, and from what I can see, if I break the bellcrank by trying to bull it apart, I am up that well known creek without propulsion.
(Related, unimportant question, why is there a restrictor orifice on this vacuum element?)