I've seen everything from a dremel, to a saw used on these guys. Depends on how much stress you want to cause them. Usually the few heads that get in the way will heal and keep growing. They're pretty easy to frag. That being said, if it is a legit Agent Orange, it's worth some money (at least by me) so I'd let it grow.
Feed it some mysis every other day or every 3 days, mine have been growing like crazy since I started feeding them.