You can't simply remove a few screws and knobs and pull the plastic bezel away from the instrument housing. If you wanted to pull the assembly out just at enough to change all the light bulbs, you might not need to separate light switch or wiper switch knobs and bezel nuts. Maybe not feck with the climate controller. I can't say I've ever taken one halfway out. Anyway...
How to R&R the inst' panel is found in factory service manuals. Many of those are free downloads. Up to 71 model is the same procedure.
It doesn't say anything about removing front seat or laying in the floor. You wouldn't set a front bench out by yourself anyway.
At the same time, The following isn't in their instructions either.
The speedometer cable is captured by a sheet metal strap under the drivers seat area. With the cable freed there it will pull it into the cabin ( the opposite of how it was originally assembled ). I actually use that cable to push a otherwise freed panel out of the dash 6 inches or so. Of course the steering column was dropped. If I'm completely removing the panel to the workbench, the speedo cable is the last thing disconnected and the first thing reconnected. It serves as a helper/extra hand. Eventually I'll have to go to the firewall grommet and push the cable back outside while maneuvering the inst' panel back into the dash opening. Beyond jacking the car up a bit to reach that sheet metal strap, What work isn't done while on my knees outside the drivers door, is done while sitting in the seat(s).