Blue Tang will not leave birdnest colony

[bigzman]

Need a bit of help. I have a 3 inch hippo tang that has taken refuge in my large pink bird nest colony. Problem I have is that I need the space and need to remove colony as a whole but every time I approach tank Hippo hides in it and it will not come out. I have tried food and he comes out but as soon as I make a move it darts back to colony. Don't want to trap or stress it out or trap it. Any ideas on how to discourage fish from hiding in colony?

Thanks