Instead of attempting to pull the connector out of a cartomizer, I found it much easier and quicker just to cut the bottom 1/4'' off with a dremel and a cutoff wheel. It is easy to deform the carto tube in your attempts to pull that connector out.
Oh yeah I never even thought of that, good idea, I think it just depends on the atty or carto cuz my tube came right off pretty easily but this sounds good for stubborn ones.