Hello. Picked up an Olympus Zuiko 55mm f1.2 in poor shape Fortunately, the glass only needed a good cleaning. A few very minor blemishes left but very minor. OK, 2nd problem, the focus ring is not linked to the mechanism. It rotates freely and the lens doesn't focus at all. I removed the rear mount, hoping I could take the focus ring off and get a look at the problem. But I still cannot remove the focus ring and now I am not sure if I can remove it at all by going in through the back. Does someone have a diagram or instructions on dissembling this lens?