A friend of mine had a huge Galaxea. We took it to Fish 4 You so he could cut it with his tile saw. He tried that and found that the water spray was destroying the tissue so he took a hammer and chisel and broke it up into about 4 pieces. I have a nice piece of it in my tank. Came though the process without a hitch.
Aside from fragging the rock up with the Galaxea I don't know though.