Go ahead and frag it. Just do it outside the tank--and use gloves--these guys STINK and it is hard as all get out to get the smell off your hands.

Just whack off the head--I usually do it at the base-- and cut it into pieces. Be sure to have some stem included with each piece. Set each frag on a rock and wrap with bridal veil to hold it on. You can probably take off the veil in less than a week. These guys grow FAST and lots of people like toadstools. Before long, you won't even be able to tell you fragged the big guy! ;)