Lens was locked to AE-1 body so tight a strap wrench would not remove it. Channel Lock Pliers were needed 6 the whole Lens rotated, not just the Lock Ring. When removed a screw fell out, but the Lock Ring still does not rotate as it should. Also the sliding Focus Sleeve is way too loose as if it would fall off. Even so, the lens does work properly, even Macro. how do I pull it apart to repair???