Hallo there, I recently acquired a copy of the first version of this lens (MD Rokkor as opposed to just MD, cosmetic difference as far as I'm aware) and the focus ring turns alright albeit seems to sometimes slightly catch on something and feel a bit of friction. As such I was wondering if there's a guide for its disassembly anywhere?

I've taken apart the Rokkor 58 1,4 for which I found several guides, both on yt and elsewhere but have not managed to find a single guide or diagram for this lens.