For picture storm windows (those screwed on outside a non-opening
window) which have become hazy inside, is this right?

1. Have a partner. 4x6 windows are heavy.
2. Unscrew the screws, holding the window in place while you do the
last ones.
3a. Take the window off.
3b. Pry the window off carefully if it's stuck, without bending any of
the metal.
4. Clean the window. Make sure it's dry so you don't introduce
moisture inside.
5a. If the window used felt around the edges, make sure it's in good
shape or replace it.
5b. If the window used felt around the edges, consider taking it off
and using caulk, for felt could be the reason the window got dirty on
the inside in the first place.
5c. If the window used caulk, remove the old caulk and use a fat bead
of butyl or elastomeric caulk on the casing. (Do not use silicone,
which makes future repairs or replacement more difficult.)
5d. If the bottom was caulked, be sure to not put it where there are
weep holes in the bottom.
6a. Replace the window and screw it in.
6b. If any of the screws don't go in straight, or all the way, as can
happen with projects like this, remove each of those screws, put caulk
in the hole, then replace the screw. This will prevent air and water
from going where it shouldn't, causing you to have to clean the window
again sooner.