How to season a giant cast iron cider press? How do I season an antique cast iron cider press that I just bought? It is substantially bigger than any stove, oven, or grill that I own, at about 48" diameter.

I'd consider other food-safe finishes too, but seasoning seems the obvious choice given that it is cast iron.
I would not heat up a large cast iron press - too much to go wrong there, little benefit. You are not frying on the thing.

Clean any oil/rust that's on it, dry carefully, oil it with mineral oil or wax it with beeswax (or paraffin wax, but beeswax will probably stick better,) use it, clean it up well, dry very carefully, and re-oil/wax before storage.