Disassemble front element of Ricoh Auto Rikenon 400mm F6.3 Lens
I've got a fungal growth inside of the front element.
I have read the cleaning answers given, and am quite prepared to undertake it. However the sealing ring does not have any holes on/in it (just writing) for a lens spanner, consequently there is nothing to get a grip on and have failed in all my attempts to unscrew it. This of course this means I can not remove the front lens so as to access the fungus in behind.
My question: How do I remove this sealing ring ?
P.S It is definitely screwed in - I think.