This video explains how to disassemble a Minolta 58mm f/1.4 PF MC lens to clean the oil that leaked into the aperture. This video just shows the disassembly and cleaning as it is part 1 of 2 videos. Check out the next video following this one to see how the lens is put back together once cleaned.
This can also be applied if you have haze of fungus in the elements between the iris.