You have to lift up with the side supports and the bucket to pick up the backhoe assembly and take the tension off the pins. It gets easier after you've done it a few times but you will want to have the tractor at idle when you're doing it so then it's less jerky and easier to move just a little bit. If you look on the John Deere website I believe they have a parts diagram and let you see how everything goes together and they might even let you download a manual but I'm not sure on that one.
You could also search on YouTube for removing John Deere model 7 backhoe. That should get you a little bit better idea of how everything goes together.
Make sure that after you pull away a couple inches, you you stop, shut off the engine, disconnect the hydraulic hoses and reconnect hydraulic hoses on the tractor side back together. If you don't reconnect the hoses on the tractor side back together, you WILL fry your hydraulic pump in short order and that gets expensive in a hurry.
Aaron Z