I've cut FC rods with a hacksaw - do it underwater or with plenty of running water on the cut.
You might be able to slip the plastic off if you heat it all up to around 300 - 400 degF and use pliers on the rod and handle (twisting and pulling apart), but that's just a guess.
You could saw off the plastic close to the rod with a hacksaw blade and then rasp/file the rest away.
Chuck it in a metal lathe 3 jaw chuck and turn the plastic away.
... and so on. But I'm guessing that FC is relatively weak and subject to brittle fracture if you load it very much. Still, a very interesting idea! Let us know how it turns out, please.
Regards,
Tom