How do you detach a leather coral from rock?

I have a leather coral (kenya trees) that are growing out of control and spreading from rock to rock. I need to get them under control. How do I detach a leather coral from the rock it has spread to? I can't remove the rock itself, as it is a large rock that is integral to the rockscape.

Do I try to uproot it like a weed? Do I cut it? Any advice would be helpful.

 

Cut it as close to the rock as possible with a very sharp razor and stick the clipping in the sand bed with some shells under it.

~Will.

 

And the small piece that is left on the rock will not re-grow?

 

smeer some kalk past on the stump that should take care of it.