Question for HubTamer experts

I am trying to position the yoke (bracket) for pushing the hub out of the knuckle with a sleeve and a forcing screw. The yoke does not hold tight against the back plate (not the dust shield), even after removing the parking brake components. Any problem C-clamping the yoke to the knuckle to get a firm support for the forcing screw? The Bearing replacement How to alludes to a similar problem, but I don't understand the reference to "persuading the dust shield".
Comments and suggestions are appreciated!
wolf33h