Tightly woven steel filament round copper 3 strand.How to remove?

I know plastic in my experience will break if you use a sharp chisel. If I have something stuck to a nice chunk of change pipe, then I just break out my steel chisel and usually after 4 or 5 hits the plastic joint breaks away. Job done. But freezing also works. If you can plug both ends and fill with water, that's the best. Since water expands when it freezes, the ice will do the work for you. I've tried that method a couple times, and it all depends on how tight you can plug the ends. They must be strong and completely watertight.