It will have grown into the smallest cracks in the rock that you can't reach, and if you remove it and/or scrape it away, it will likely grow back.
I tried for 4 years to scrape away that red monti and it always grew back. I've placed rocks on top of it, tried to glue corals on top of it, I tried just placing a blob of glue on top of it, it always grows back from under. Its a weed coral.
Finally I just pulled the rock out. IMO if you want to move the coral then will need to move the rock. Good luck.