You're supposed to use special hooks that slide in-between the panel and the dash and just pull it out. What I like to do if I don't have them (your case) is to remove the speaker cover and speaker form the dash. Then simply stick your hand behind the cluster and push out.
The older clusters have many wires and light bulbs. Make sure to write them all down. They should be numbered but the numbers usually fall off. Especially if the cluster has been removed before.
When removing speedo you'll need to loosen the brown panel in the back (2 screws like the ones for speedo)that holds the fuel, temp, etc. It's just to give you enough clearance to remove speedo and reset linkage.