Removing heater control assembly, 1984 pickup

I'm trying to figure out how to remove and repair the heater control assembly (home of the cables and levers for the heater and vent system). I'm not sure where to start, where the screws or bolts are located, and how much comes out in one piece...ie: is the panel part of the control assembly?

Can someone point me in the right direction, my factory manual doesn't think this is important enough to include.

jc