how to remove wiper arms

as I recall there's a knurled shaft and a keyway...and a keyed blind knurled insert on the wiper arm...this key should stop the thing from turning about the shaft and is a press fit as I recall....so check the "key" or piece of spring metal which keeps the position...may have fallen off or got bent...but align the key to the keyway and push~....to un-install there's a small puller....rent one from autozone~...or tough it with a couple of large screwdrivers twistin at the base in tandem....good luck~ if it's looose and floppin willy-nilly this and that all sixes and sevens would look for the missing retainer spring...like I say~

If you haven't replaced them yet, get them from Autozone. It takes the guy (of gal) behind the counter about forty seconds to replace them once you clear the exit door. And the guy who changes mine only uses his hands.