Radius ball replacement

[Stingray70]

Hi guys. The only thing left to rebuild on the 30 Coupe is the steering and front axel. I am in the process of repairing the front radius rod because the ball is severely worn. It is just a nub, about 60% of what it should be.

I purchased a replacement ball from one of the good vendors. The installation instructions are terrible so was hoping to get some advice on how to install it from someone who has experience.

The instructions say to cut off the old ball leaving 1/4". The new ball has a slotted shaft on it. Am I supposed to cut it off? Or Grind the 1/4" bit to fit in the slot.

Just as importantly is how does one get the new ball aligned perfectly. The old ball is so far gone, I can't really make a jig...