I don't know if this is the correct way or if it harms it but I ended up gently and slowly twisting it to the edge of the rock and I finally got it off. There were a few of the byssus strands were still attached to the rock so I don't know if this hurt it or not but I have moved mine quite a few times and it is still alive and perfectly healthy. From what I understand they excrete the byssus which hardens to the rock and they hold on to it. So I don't know if mine let go of the Byssus strands or if it ripped the foot but like I said mine is just fine.