I have to change the rear wiper arm hub on the rear windshield of a 2009 Grand Caravan. The wiper arm broke off leaving just the hub on the glass, which I cannot figure out how to remove. So far, I tried spraying lubricant on it.

 

I have an '03 and just took mine off. had a nut you remove then rock the arm back and forth to get it off. used some brake cleaner on it to clean. then some wd40. don't think i would use grease though. have had to do this several times