I just did this in my Alpine. No need to remove the windshield or the dash pad. You will destroy the dash pad if you remove it anyway!
Take off the steering wheel, turn signal switch, and surround for more working room. Remove the large phillips head screws you can see on the dashboard face. Remove the lower padded dash pad and steering column support assembly. Now you should have room to remove each gauge and wires from each and remove the heater control cables. I had a hard time removing the speedometer as the cable did not want to come loose and the gauge bracket was on tight. Make sure you label all the wires! Have fun…..Eric