first ill take a screwdriver or chisel with a thin edge to get in between the polyps somewhere and take a hammer to break the rock up...once it splits, most likely there will be a part along the break that you can get under a lot easier, you i take a screwdriver, or something small like that to work with, since most rocks are completely flat to just scrap off...right now i just bought some of those mini screwdrivers to try out...on bigger zoos like palythoas and some you are able to work with a lot eaiser as the base of their stem seems harder, and dont grow quite on a mat like some, and eaiser to just pull apart.