[Renoir]

Spray Corrosion Guard (or similar product) to penetrate the assembly. let "soak" for 24 hours. Place the whole end into a bucket of ice water. Let soak for 20 min. Meanwhile heat up a hot pad on high. Pull out assembly, wipe off and wrap surrounding metal with hotpad avioding contact with the rod as much as possible.

Affix rod into a Workmate (or similar device with soft jaws), use an air chisel with a blunt end against a block of wood (may take a helper to have another set of hands) to "hammer" with a higher frequency than manually is possible to shock warming metal longitudinally against affixed rod.

Good luck with patience and tolerance.