1966 valiant rear brake shoe removal?
I've always just used a good big pair of pliers--slip joint--Grab the outer cup with the pliers so you can apply inward pressure, and reach around behind and hold the stud "out" against the backing plate. Plus in, give it a 1/4 turn in either direction and it should come right off
As old as "these girls are" you should replace those if you can get them...likely rusty and weakened.