My vice has a circular 'crook' in the back of it behind the fixed jaws. I just sit the victa bosses in it and hit them with the hammer, they pop off the crank pretty easy.
Basically you are hitting the steel to deform it so it will let go of the taper lock. They are not that higher grade of steel and can be damaged, take care with the corner where the blade disc sits. More so the power torque ones as they are thinner but you can flatten them to the point where they will split.
Not all full crank bosses are the same either. Depends what motor it is off. See blumblys thread on the cranks.
