I know what you mean about the colt. I got mine about a month ago and it is about 4x larger now.
That site points out how to take frags [niping small pieces off] to make several more corals, which I'm not sure that is what you want to do. I have never fragged, but I believe with the colt, if you see a column completely spliting off, you can simply divide the specimen using a sharp razor where the 2 columns branch off. You can mount using superglue gel onto a fragment of live rock, or, if you know exactly where you're going to put the split pieces, then just glue it there.
Keep in mind, as I said, I have never fragged before.