Removing the Front Element of a Leica R 90 Elmarit

I have an R90 2.8 Elmarit that has a messed up rear element. It takes great photos, but it bugs me, so I bought a bgn R 90 Elmarit in the hope of swapping the rear elements. The elements came out fine, but the tolerances are different from lens to lens, so the new rear element didn't want to easily go into my old lens, so I put everything back and decided to just give the bgn lens a try. Trouble is, that one has some oil residue inside the front element. Not a lot, but I'd like to clean it. Does anyone know how to remove it? There's a ring around the front that has a small screw, but I think I removed that front cover once on another lens and could see no way to get the element out. Maybe a suction cup deal? Anyone ever had one of these apart?

messed up

I am curious how a "messed up" lens part can still take great photos. But I must say you are a brave person -- I'd leave it to a professional, being that it involves such a fine lens.

Well, it takes photos like this. I also am mystified, but the proof is in the pudding. The rear element is almost opaque and looks as if it's been peppered w/ salt from fungus removal. Works a treat though. I'm pretty handy w/ cameras and such. Just need to know how the front is put together before I tackle taking it apart to clean. Most of this stuff is just common sense, but product knowledge can save you a lot of time and work.

Why don't you post a photo of the front of the lens, as well as the small screw that you mention.

You might want to ensure that the lens focuses to infinity. Sometimes, you can mix and match lens elements. Sometimes, you cannot.

With higher priced optics, all of the elements in a lens are part of a matched set.

However, this might not be true any longer.

At the least, make sure that the lens focuses to infinity.