I'm removing the pass. Side fender but can't remove the antenna base because of the corrosion. Anybody have any solutions?

 

Break it off?
What year/ model?

Penetrating lube and HEAT are the time-honored favorites.
Sometimes you have to sacrifice one part to save the other.

 

1965 cutlass, hate to break the antenna housing. I'm letting it soak with penetrating lube. heat will melt the rubber gasket.

 

TOO MUCH heat will harm the rubber and etc.
Use less heat.
Think hair dryer or heat gun held back a bit.

Penetrating lube, then wiggle back and forth with a LOT of patience.
Do you have the perfect correct tool for gripping the thing you need to remove- pin wrench or whatnot?