Frank,
Converting to mediums from deeps is really quite simple, if you are going to
do it next year.

Buy your medium bodies now and foundation, After thorough painting, put JUST
ONE on top of your 2 deeps now and FEED 1:1 sugar syrup to FORCE them to draw
the foundation and maybe you will get some fall flow of goldenrod or
something (I don't
know your location).  If you can get the frames drawn and filled with honey
or sugar syrup, leave the mediums on for the winter in the TOP position.

During the winter the bees will eat their way UP from the bottom deep into
the 2nd deep and medium.  When the bottom deep is EMPTY (probably in January,
remove it.)
In March add the 2nd medium of foundation and again, CONTINUOUS 1:1 sugar
syrup.
When about 6-7 of these 10 frames in the 2nd medium are drawn and filled with
something (sugar syrup, pollen, or brood), add the 3rd medium of foundation.
When
6-7 of those frames are drawn and filled with something, add supers. Remove
that 2nd deep whenever it becomes empty of brood.

Depending on your location, you should have no deeps and at least 3 full
mediums by May or surely June.

If you are going to use queen excluders, which I strongly endorse, do not add
the excluder or any honey supers without asking me for advice; because those
new supers will have to be "baited" or bees will not pass through the
excluder.

Hope I have helped.

George Imirie
69th year of beekeeping in Maryland
Certified EAS Master Beekeeper
Author of George's PINK PAGES