Is there a trick to removing the wiper arms?

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Not the blade inserts, and not the blades into the wiper arms. I'm trying to remove the full wiper arms themselves. The black paint is chipping off and or badly worn. Need to repaint 'em.

I've removed the 16mm nut no prob. But after that, I have no luck in pulling or prying off the wiper arm from the threaded shaft. I don't want to damage the wipe tie arms underneath. How do you remove these pups? Any cautions?

Secondly, do you think repainting them is not a good project (paint will wear quickly), and maybe I should just buy new ones? Are new ones expensive?

Thanks guys!