The best way, and this can be done with any set of cutters....just slightly close the cutters around the coral and twist the cutters to snap the coral...don't crimp closed to cut, this can lead to the more tissue damage.
You picked one of the easiest to frag SPS's to practice on You can't mess this up (knocks wood....LOL). The tall straight branches on the Tri-Color makes it a cakewalk.