First unlock the cam lever by movining it vertical to the vise jaws.The set screw by the vise jaws should be loosened if needed to accept the hook. Tighten this set scew with the hook in the jaws until it is snug. Then close the cam lever to the horozontal position.With the hook secure you can rotate it's positional aspect by losening the thumb screw by the wheel . By frreing the shaft you can use the vise as a full rotary or you may tighten the thumb screw to hold the hook in a desired angle.
Hope this helps, Fred