Split it as in what? If you meant by fragging, then yours look a bit too small to frag, give it some time and it'll form an umbrella look or mushroom look then just cut around the middle 'stem' part with razor blade, scissors, knife, whatever sharp. Put it in low flow area with live rock rubble and it'll attach itself. Honestly I haven't cut the 'stem' itself, it might probably work but id rather not risk it, as all the polyps are gone. Might take a while to grow back. So I don't think you should cut it off the rock. Don't use glue or epoxy to attach these guys, soft corals tend to slime when glued or epoxied and won't work(some people had success though)
And if you mean by splitting them away from each other, then just use a saw, dremel, bone cutter or some sort of cutting pliers and just break the rock in half. Or saw your way through around the coral so it'll have a thin layer of rock and you can easily glue that to another piece without sliming/harming the coral with glue.
They aren't too sensitive about air, they can last quite a while. But you can always frag it in a bowl of saltwater.
