Wiper arm removal

I modified a pair of these to work. If yours has been on there 40 years it may be stuck.
Take the solid piece out of the jaw. May need some grinding or welding. Can't remember. But the principle is there.
http://omegatec.com/k-200CG-clecos-pliers.aspx?gclid=CLvTqNvexrgCFWIV7AodYV0AwQ
Lift the arm up to help take the spring tension off from pushing down on the pivot in a cocked fashion.
Then you can push straight up on the base. Put a pad between the lower jaw and your car.
Maybe they make a tool. But I don't know about it.
Later wiper arms had a little clip that retained the base to the shaft. You lifted the arm up like said above, push the clip to release.
I don't think yours has the clip but be sure and check.