Do you still have a queen, when you do the split (sounds like you do)? If so, just split the hive in half, be sure to put frames with brood, Q cells, pollen and honey in both hives, put the brood in the middle of the bottom deep. Try to move the existing queen to the new location if you find her. Reduce the opening to the medium opening, put grass, or a branch right in front of the hive to re orient the bees to the new location. The older bees will probably go back to the old location. Do this for 2 reasons. One, to make the Q think she swarmed. Two, this leaves more bees for the new hive, it will be another week or so before the new Q will be laying eggs, maybe 2 weeks before she is laying large numbers of eggs.