Kenya Tree and Xenia Removal

[reefbyremote]

My kenya trees and to a lesser amount xenia and GSP are starting to grow well- and even getting too big. I need to cut the back and in some cases remove pieces, in particular the kenya trees. Its smaller pieces are easy enough to deal with but does anyone have any hints about how to successfully remove bigger pieces so they do not grow back? I can "tear" them off the rock but the foot is left behind which I imagine will grow back.

Thanks in advance for ideas. Oh and if anyone wants pieces and is in Medicine Hat let me know.