|I've only had my dash out twice and wasn't concerned about time-and-motion studies either time, so this is only an estimate based on recollection.
To R&R the steering wheel, instrument pod, driver's side sub-dash, glove box, glove box pivot rod, transmission console, heater console, miscellaneous trim, heater tubing, and main dash assembly, I'd guess about two and a half hours to remove, and the same to install. This presumes a brisk and agile mechanic with prior experience, and that the hardware is no more than typically stubborn. If things are rusty, add a quarter hour for applying penetrating oil to all the fasteners. If the heater control cables are disturbed when the heater console is removed, add a half hour. Custom sound systems would also add time.
You should also figure that the car could be tied up for three days to several months if any major parts happen to get broken during the process, and that someone other than yourself should be the one paying any storage fees that resulted.