Jeff zone 8 N.C.

I assume it would be an in ground plant. I do not know if this would be the best way but it is the one I have used successfully before. I would cut off the mother plant near soil level and then kill the mothers growth point by cutting it out, leaving as much intact corm as possible. Then I would remove the undesirable pups completely from the mother corm. That would allow the preferred pup to feed off the mothers corm reserves. I have done it another way by just cutting the undesirable pups off above ground and then keeping any of their replacement growth cut off.