You have to get under the dash and remove the nuts . It can be tricky because there hard to find . The ones that are really hard to see I believe are one all the way towards the passenger side and I believe two above the bezel area . You can reach your hand up there and feel around .
i dunno if they make or have an assembly manual for yer model, i'd imagine they do... i'd recommend getting one. prolly costs 20-25 bucks. it's one a those "can't do without" items. check yer local restoration parts supplier for availability... you won't regret it
If he is trying to fix the speedometer, I'm gonna bet he is removing the instrument panel, not the dash pad. Is that right Nasrock?
If so, you have to remove the screws along the bottom edge of the instrument panel, and the lower steering column cover. Remove the screws along the top edge that hold the instrument panel to the dash pad. Remove the screws that hold the heater control in the dash. There is one more screw on the end of the dash that you can only get to with the drivers side door opened. Remove that one too. Finally, to get the panel out, you will have to lower the steering column. Remove the 2 nuts that hold the steering column up to the underside of the dash, and let the steering column down. You should be able to gently work the instrument panel out now. I have found it is easiest to start the top out first, then you can pull it toward you, and up at the same time. Once you have it out enough to reach to the backside, you should unplug the speedometer cable, and unplug the instrument panel connector.
Gentle is the key here because the instrument panel is old, and brittle. Too much forcing will break it. Finding a good replacement will break you!! If it doesn't come out with just a little effort, check for something that still needs to be disconnected.