C3 is a very full hive as you can see in this picture (taken at Beemaster central the day before I took the girls for their road trip).

John gave me a extra deep super and I just got finished assembling 10 frames and foundation (This stuff smells great!) and would like to add it tomorrow to give them more room. There seems to be a extra 3/4" of space in the super. Right now there is a lot of brood in the upper super and more honey in the lower. I was thinking of switching upper and lower and putting the empty super on top. Would this be the best way to do it? Any help? The hive has a beard on it like in the picture and it's 10:30 pm. I would like to prevent a swarm if that is even possible.
Thanks