I have an AC condensation drain pipe that is cloged with too many elbos to snake. I need to remove the PVC pipe from the cast iron nipple that comes out of the Air Conditioner. How can I do this with out breaking the PVC?

You can't. You cut the PVC pipe, then put it back together with a coupling.

I have an AC condensation drain pipe that is cloged with too many elbos to snake. I need to remove the PVC pipe from the cast iron nipple that comes out of the Air Conditioner. How can I do this with out breaking the PVC?

Hold the phone! You don't snake a AC condensate line. Do what I do when I get a call of water leaking from the air handler. You line's probably loaded up with gunk.
Take a air bottle or compressor and blow the line clear from the air handler. Once clear go down close off the end. Fill the line with bleach and let it set for a spell. Drain the line and you're back in business. Good luck, Tom