You seal the edges so the laminations don't separate. Remember, this is chinese grade cheap carbon fiber. It can and will come apart. And putting some CA on the edge will help add a little strength to it as well.
I always used a dremel or a die grinder with a standard metal cut off wheel (abrasive wheel). Just be sure to wear a dust mask and eye protection. This stuff sucks worse than fiberglass lol. And it is pretty strong, much stronger IMO than any fiberglass out there. But it cuts about the same. Just takes a little longer.