I made the mistake of placing it on a structural piece in my tank which I've been battling it by every couple months blasting one side with a pump which slowly kills it then switch it back like a yoyo effect lol. You can also use epoxy or putty to just cover it up to kill it. You can try peeling it off but most rocks I've seen will have too many nooks to really get it off...
Edit* you could try breaking a frag off which you could keep and sell the large colony off for a free frag in a sense.. then you could place it better and have it fit the tank more to your liking