Please excuse the CNC but not specifically Tormach related question.

I use a Fowler 25mm X-TEST Test Indicator 52-562-007-0 to zero my Tormach on a round feature. The pivoting shank is great to set the indicator to sweep the right size circle.

My problem is that the screw that holds the dial to the case has come loose and blocks the hand. How do I remove the crystal? I hate to destroy an otherwise good indicator by doing the wrong thing!