I tried to open my (1985 Silverado C10) vent window the other day and the bottom connection snapped off. So I took electrical tape and taped it in so it wasn't so noisy.
How much trouble is it to fix or replace it?
It's a pain but not horrible and you should be able to find the assembly in the junkyard. That chrome post that it latches to is part of the vent window. Once unbolted, it slides out of the door. You have to have the window down and remove the door panel too. If I remember, there are 2 or 3 bolts there inside the door