There is usually a lot of slack in the speedometer cable (maybe 8 - 12 inches) that can be used to easily access the clip (the one Robert shows above) - without the hassle of laying on your back and reaching up from under the dash.
On the engine side of the firewall, locate the speedometer cable:
You must be registered for see images attach
You must be registered for see images attach
Clean and lube the outer sheathing with WD-40 and push a little bit through the firewall.
You won't be able to get much through at first because the cluster will still be stuck in the dash frame.
Here is the trick to releasing the cluster bucket from the frame:
The bucket is designed to be inside (towards the firewall) on the bottom lip and outside (towards the steering wheel) on the top.
Pull the top of the bucket in towards you - as far as you feel comfortable with. Then reach down and push up on the bottom of the bucket until the lower edge can clear the lip of the steel frame.
It may take a little finesse, but at some point you'll have the top and bottom popped out of the frame.
Now you can go back under the hood and push as much of the speedometer cable through as you need to disco it.
Once the speedometer cable is off, it becomes much easier to unclip the wiring harness from the PC board.
