Chad,
It sounds like maybe you have some baby buds sprouting at the main branch, you can check at night or early morning just after the lights come on to varify, you will see tiny new crowns developing.
If it's budding new crowns then simply wait until they are about the size of an almond and then you can break them off with some gentle needle nose pliers and glue them to small pieces of live rock.
If your main colony is propagating by division then it's a whole different ball game, as you should not try to cut the main crown in half-it will seperate all by itself over some time. Once the main crown has formed two individual crowns, you can then cut the branch between the two crowns.
Simply cutting a main crown down through the center of the live tissue will most likely result in two dead pieces of coral due to infection or stress.
I have fragged my frogspawn about 30+ times now and I always let the coral do the seperating first, then I just split the crown at the base of the branch or I pluck off smaller developed buds from the sides of the main branches.
Goodluck
