Simply unscrew the housing. Clean everything. Be very careful working over the top of the aperture blades. I always leave the blades wide open to prevent possible damage if I drop something.
The white specs are a form of fungus that was growing on the element seating surfaces. Use hydrogen peroxide and ammonia on a cotton swab to wipe the surfaces down. They wont disappear but the spores will be dead.
Another set screw--This time no super glue! On the mid element housing, you will see a brass ring with a single set screw. There is no reason to remove this element from the housing since you have access to both sides of the element to clean--However, I am through and wanted to inspect everything for more fungus and remove all dust and debris from the lens. I want it to last another 60 years!