I have a 4A and took my dash out two years ago and replaced it with one from Randy Keller in Santa Ana. He is terrific. The following may be more than you need or want, but:
You will want the center console, tunnel hump bracket, glove box and all switches on the plinth panel removed. You'll also want the lower dash pads removed.
I had to reach up behind, on my back (easier with the center bracket console removed), and remove all of the U-shaped gauge brackets. Maybe it's easier since you removed the upper dash pad. Have wire marking tags and a pen ready, however, because a few of those brackets have ground wires attached, you'll want to remember where they go. One grouping of black ground wires should be fused together.
After you remove those brackets, and of course with the battery disconnected, you can reach up and remove all of the other wires and tag and mark them. All wires were removed before I pulled the dash. I had insufficient wire length to pull the dash forward any appreciable distance (old wires can be brittle), and since I was under there and had to remove all the switches and the choke from the plinth panel, I went ahead and disconnected and marked all the gauge wires at that time.
I found a little Ace Hardware head strap light to be invaluable in this process.
Once you have those brackets and wires removed, including from the tachometer and speedometer, and including removal of the ignition light and turn signal indicators above those gauges (they screw off, but be careful not to scratch the chrome or your dash), and after you've removed the dash pads on the sides, the plinth for the switches, and all dash screws, you are ready to remove the dash.
Good luck on yours.