I'm changing the gas tank on my 95 Cavalier and despite blowing the crud out with compressed air and using the correct tool cannot get the fuel line fittings to separate. Does anyone have any ideas or suggestions on what I can do? Perhaps the connectors are just too rusted and they just don't work anymore. In that case how do I replace the connections? Any help is much appreciated because I am totally lost on this one.
Try pushing the lines together while you're pushing the tool into the collar. Also twist the tool a little. In the collar there are 2 tabs that are slightly bent in, there is a ring on the line without the collar and the tabs push against it, holding the lines together. When you push the tool in there you are spreading those tabs apart and away from the ring, so the tabs no longer hold the lines together.
Once you get the tabs spread (it will kinda click), pull them apart. It's tricky, but don't give up, or find a friend that can change a fuel filter on a Ford truck.

Listen F***ers. FASTERTHANAHONDA is a joke because I WORK FOR HONDA. I'll talk @!#$ about Fords to, that doesn't mean I can beat a 12 second mustang.
Thanks, now that I can picture how it works inside maybe I figure out how to get it apart.
I think what's wrong is that there is rust inside the connector causing the plastic to bind. How in the world do I replace those fittings if I need to? Or do you have any other suggestions such as maybe the plastic in my connector tool is possibly too soft. and a metal tool would do the trick. I'm almost ready to bring the car to the local dealer but if they have the same problem it's going to cost me an arm and a leg but I'd rather fix my own car if I could just figure out how to get the lines apart.
Tools
Those are my favorite style tools, the ones on the top. Just keep at it. It took me 15 minutes on my first line and my boss got the other one of in less than 10 seconds. Seriously though, find someone that has done those lines a few times. It gets easy with practice. GL

Listen F***ers. FASTERTHANAHONDA is a joke because I WORK FOR HONDA. I'll talk @!#$ about Fords to, that doesn't mean I can beat a 12 second mustang.
I bet I could have done it with the anodized aluminum tool you suggested because it's harder than the plastic tool I was using. Makes no matter now because my wife felt bad for all my struggling and decided with me to take the car into the dealer to change the tank. $240. later new tank is installed but I wish I would have known about that tool sooner. Oh well, next time.