Just cut it in half. I just cut mine about a month ago and gave 1 to my uncle. My half is looking very good and expanded, stretching for light. My uncle's crawled behind his rocks and sticks a few tenticles out (he's got a giant gigantea carpet a few inches from it, they're not getting along).
It looked like I killed it the first few days, but now it's bigger than ever, and I'm thinking of doing it again. If you cut it, make sure it's mouth is cut in half - right down the middle. It's messy, and after I did it i figured I just killed it (I was a little rough with it). But I didn't. They say cutting them is a gamble, but I needed to try to calm it down - It kept walking over my corals, so it needed a "spanking". I've been feeding it silversides everyday for the past 2 weeks.
p.s. Thanks for the rock. pm me you're email address again and I'll send you a pic of my RBT (in a 29 gal)after 3 weeks of cutting (it's already 6-8 inches from 10-12) and a pic of it in my 75 before I cut it (9 months ago).