With the HINGE SCREWS removed and the HINGE drum and cover
drum removed you may now remove the COVER.
now have just the RING PLATE to deal with and install on the
wall where desired.
installation of a Porthole is to have the HINGE at the TOP of
the unit when in place, This is done on ships and boats so that
they can be closed easily if water is coming in hard. It is
easier to close a porthole “Down” when water is coming in.
in a house or building can be any way desired.