clutch disc not releasing help!!

Out of the MP book this fixture is for setting finger height on a B&B plate.

It does not give specific directions for use. My take on it is you replace the clutch disc with the fixture (0.310" thickness) and the finger heights should show 1.700" on all three.
Adjust the eyebolts as necessary and stake the nuts to keep them from turning.
A new plate I found one finger off 0.035". So just because it's new doesn't mean it's good.