How do you remove the speedometer cable from the back of the dash cluster of a 1965 ford ranchero?

I think theres a few screws that hold the cluster inplace, once those are out you should be able to pull the cluster away from the dash a few inches. You will be able to see the wires that go to the fuel and temp gauges and the lights that should just plug into the back of the cluster. Be sure to mark your wires so you can put them back when you put it back together. Now as far as the speedo cable it should just unscrew from the back of the cluster, it will be a large cable that connects to the back center of the cluster. If your concerned about how it will go back together you take pics as you take it apart as a guide. Good luck hope this helps.

This video is for a 65 mustang but it should be the same as the falcon/rachero the even though the video is for a rewire it shows how it goes in the dash. Cluster install starts at 3:05 in the video: http://www.youtube.com/watch?v=aE7YDDxCdN8

If disconnecting the cable is all you're after, there should be a plastic collar (usually white) where the cable meets the Speedo. Disconnect the cable from the trans and loosen/disconnect any anchors so you can pull the cluster out further so you can see the connector I mentioned. Usually, you either pinch it or push it to one side - it's been a long time since I've messed with a speedo but I've done a ton of in the past.

Tracy has it right, I was able use a screw driver to release the white clip from the back of the speedometer.