Caustic soda. Abrading it a bit first might help, as decent caustic is hard to buy you could try oven cleaner.

When the finish is off go through a couple of grades of emery paper used wet before going to the buffing wheels.

Quite straightforward as long as it's a part you can fully remove.
Take care with caustic, do it outside, long sleeves, mask and proper googles not just specs and a readily available source of water in case you do "get it on ya".

If its the soft Type 2 then as LTFK suggests a brass wire wheel, emery etc will easily remove it.