I personally haven't completed the process myself but have read enough to learn that if you intend to square up the "Inside" jaws you would need to apply an inside the jaws jig and apply closing pressure!
By placing a ring around the OUTSIDE portion of the jaws and then applying tension by OPENING the jaws (by turning chuck key in counterclockwise direction) you apply pressure in the wrong direction for the intended preferred outcome. If you then proceed to grind the Inside Jaws you will definitely st rhe very least end up being in the same boat but realistically speaking the chances are your boat now has a big hole in the hull!
So to Keep it simple, you need to clamp a jig of some sort that is correctly setup dimensionally so that you tension the jaws into the grinding
stone NOT Away from it! Basically speaking, placing the ring on the outside jaws is how you setup for grinding the outside jaws.
Hope this was helpful...... please update the thread with your results and the process you decide on using