So I recently got this lens, glass is very clean, only issue is the focusing is pretty stiff. Do I have to completely dismantle the lens to get to the helicoid to re-grease it? The only suitable grease I have here is HelimaxXP which I have used on a few lenses before. I am trying to look online for a schematic or guide for this lens but I cant find one. I want this to be project for the upcoming rainy weekend. As for tools I do have some JIS screwdrivers.