When my pulsing zenia started to invade I just got my thumbnail started under the edge, then once i got it started it would usually pull away from the rock pretty cleanly, you just have to work at it slowly and keep it peeling up off the rock so as to not leave any behind.
As far as the palys, I have several rocks with them growing on it, A couple I was able to bit by bit peel them off the rocks with tongs (time consuming and tedious) on 1 rock I ended up breaking off the sps that was growing there and setting the rock w/palys outside to freeze dry. I still have a couple more rocks to do.