How do you remove this on a 70 coupe? Do you need to remove the steering column as well?

 

Theoretically. In actual practice, I have detached it from the pedal support, removed the firewall bolts from the seal flange, and lowered it to the floor.

The trickiest part is the RH dash panel, the one that matches the instrument panel, goes in and out with the pad.

 

By lower dash you mean the metal frame, correct? Well regardless, you don't need to remove the steering column to remove any of the dash. There's bolts on each side of the dash holding it to the car, two brackets near the middle, and I believe one bolt going into where the gauges would be. It's really simple, just find al the bolts/brackets and lift it over the column and out through the car. I've done it twice to my car and took out the dash on my dad's 69 as well, it only takes me 30-50 minutes.

Here's my car, no dash, column in.

 

No soundproofing on the underside of the cowl? Ford did.

 

Ford didn't on my car. I forget if I did end up putting some up there or not, I wasn't completely done in that photo.