Changing from Deep to Medium

[DayValleyDahlias]

How is it possible to change a strong deep 3 box hive into mediums?

Muchas Gras

[Ross]

Of course, a number of ways.  The most obvious is to treat it like a cut out and cut the comb from the deep frames and rubber band into mediums. 
The next way is to add a super of mediums on top.  Once they have drawn it, either wait for the queen to lay in it, or move her up.  Add an excluder after your sure she has nurse bees to maintain her. 
I usually just start removing non-brood frames and replacing them with mediums.  The bees draw them and draw some extra comb on the bottoms.  Once you have some brood in one, move it above an excluder and move the queen above the excluder.  The deeps will hatch, the queen and nurse bees will be up top.  When the brood is out of the deeps, remove and replace with mediums. 

[Michael Bush]

It's easy to get them from three deeps to one deep and some mediums by using an excluder.  Just put a medium on the bottom and the queen in a deep on top of that with the excluder over that and the other two deeps over that and let all the brood emerge from the other two boxes.  Then harvest them and put more mediums on top.  Then, if you're impatient, just do a cut out on the deep and tie all the brood combs into mediums.  If you're more patient, cut one brood comb out of a deep and tie it into a medium and put the queen in there separated from the deep by an excluder until the brood emerges from that deep.  Then harvest that. If you're even more patient, just add mediums on top and pull any empty deeps off in the early spring and wait for them to move into the medium.

http://www.bushfarms.com/beesferal.htm#moving