And if it is attached to both the rock and the glass bottom, be very very very careful. I attempted to move my blue haddoni that was attached that way. I ended up putting a hole in the oral disc. I had thought for sure that it was dead the way it looked. There was even a piece of it still attached to the glass bottom -- with tentacles.
On a whim I decided to leave it in the tank -- even though it looked god awful and thought for sure it was going to die. That was a about a month ago, and it looks back to normal now, albeit smaller.
I've seen pictures of yours, and it looks great, so take your time, and don't push it too much. I have found that they are one of the harder anemones to remove, seem to have an incredible grip.