I find great pleasure in taking things apart, occasionally I manages to put them back together as well.
As with the 75mm lens who came with my bargain 600SE. Looking trough the lens there was large amounts of dust, so while waiting for my 100-c to arrive I figured a good clan of the internals might not be such a bad idea. Both the front en the back element are easy to unscrew with the help of two hands , just a firm grip, then turn them anti-clockwise. The internals of those two agin where really not needed to take apart so I left them alone. Job done in less than a hour, hopefully bringing it back to it`s original performance.
Dusty little thing
And this was what I found on one of the elements - guess that had done something to the IQ of the lens
Next step will be to replace the broken connection between the leaver and the aperture ring.
And by the time that is done I hope my ten packs of 100-c has arrived!