Main thing is to really think through your process before you start. People can get a little overzealous and drill out spot welds they do not have to or damage things that should have been removed. Drill the old one being replaced out. If you can, grind the replacement one out of the donor car. It is drastically easier to weld in if the replacement is not full of holes. The grinding is a pain but will pay dividends on the install.
I too am curious about the dash pad. I don't have to replace the cracked unit, been that way since I bought some 18 yrs ago, but if I do I would like to know what it takes. If it's not too bad then I may consider doing it sooner rather than later.
Oh good Lord, the steel frame is not something you remove to paint on a Chevy II.
The pad can be a bear to remove as it is bolted in from the underside. I guess it is possible to get it out without removing basically everything, but I would not even bother trying. If you are painting the dash you need to strip it anyways, so its all coming apart. Might be able to pull it off in a long weekend.
I have dismantled my dash during my build. Ounce every thing is removed the dash pad is easier to unbolt. Make sure to clean all your dash and all you plan to paint with Grease and Wax remover before and after you start sanding and painting These dashes seem yo get more than their share of Silicone cleaner's over the year's.
Bootlegger's method is how you do it. Get a few cold ones in the fridge, turn on some tunes and slowly remove things attached to the dash starting from the bottom to the top, and be sure to mark and keep all the fasteners for reassembly. Done carefully, the hardware all looks right, wires go back exactly where they have been for 54 years, and the only changes are that the color of the dash is fresh and everything's clean. But getting it to the point of his picture, with everything kept orderly, is the method, in my opinion.
Yeah, I agree 100%. That is the way to do it. Big project, but if planned out, will go relatively smoothly. Good time to replace the firewall pad, rebuild the heater box, replace the various foam seals, vacuum out the half century's worth of debris in the kick vents. If you are an originality guy, great project to really get a grasp on how things were assembled. Best of luck!