Never use a sharp tool unless you really know what you're doing. Introducing palytoxin into your bloodstream via a sharp instrument slipping and cutting your finger is a really bad bad thing. I use a small flat tipped screwdriver, get just under the foot of the polyp, use your thumb (preferably with a glove), and you're "pinching" the skin of the foot between your thumb and screwdriver blade. Gently pull the polyp away from the rock as if it were a decal adhered to it. You should never pull the polyp away at a shallow angle, this will cause the foot to tear. you'll just peel it off. The idea here is to not tear the foot in any way, that way no toxin is released (hopefully), and the polyp has a better chance of survival.
Another better way is to lay a rock down against the polyp, the polyp will stick to the rock after only a few days to a week, then peel the polyp off the other rock or cut it. The remaining foot on the old rock will form a new polyp pretty soon.
