Set the cross bar of the yoke at 3/4 depth(slightly above parallel). Load it up with weight, put the cross bar on your back(same position as a back squat) and perform the concentric portion of the squat. Lower the yoke to the floor. Add more weight and repeat until you cannot perform the lift. I will shoot video of this workout in a few hours and post it here.
Post loads to comments. Video if you have it.