the age of my Yashica shows up in a bad way - I was so glad to have it fixed, when the problem occured. First I noticed some unsmooth focusing, then it became really harsh - maybe some sand got into focusing helicoid (if there is any), or just the old grease finally leaked out. How do I cure it? I understand that I would need a full lens disassemble to get the dirt out - can you give me a hint how should I do it? Can it be accessed from the front of the lens, or I need to disassemble the whole camera again?
Any help would be very nerve-saving and valuable.
Best wishes from Moscow,