Quote Originally Posted by John Koehrer View Post
There probably is enough fungus to have an effect on your pictures. Flare, loss of contrast, soft image.
The lens is till going for over $300.

The group you want to get at is held in by the inner spanner nut/ring. it's visible in the picture and is the smaller ring with two notches at 180 degrees.
A cheap pair of pliers with the tips ground t fit the notches will work. If they fit correctly they won't mark anything. Slip and all bets are off.
You may need a small suction cup to get the glass out. Clean it with ammonia and wipe the barrel out with it too.
The fungus will just get worse if you leave it there.
I agree with you John. The lens should be cleaned, and ammonia kills the fungus. 24-25% white vinegar can also be used. Vinegar is a potent fungicide.

Pliers can work, or you could make a tool by cutting a sheet of metal, and there's also spanner wrenches for lenses to buy on e*bay ( http://www.ebay.com/itm/New-Spanner-...-/200658548947 )

Whatever works, as long as the tool fits both of the notches in the lens element retaining ring so you can unscrew it.