Originally Posted by 3alarmer

This is a cut and paste from another thread with a similar
issue. Since there appears to be some confusion
between this and the Sheldon Brown method of fixed
cup removal (which this is not the same as), I will try
to post some photos for you in the next few days.
I'm kind of strapped for time this weekend. As you
have correctly surmised, your cups are ISO/English.
This should make your replacement job considerably
easier in terms of parts availability. The fixed cup
is a left hand thread (i.e. it loosens clockwise).

If there really is an ongoing moisture problem,
I would probably opt for replacement with a sealed
cartridge BB unit at this point. They are cheap and
readily available, and you most likely have a standard
JIS taper on your crank. You just need to get the
right axle length and protrusion to maintain your chainline.