The fish would likely need to be sedated to do it... dangerous unless you know what your doing ect.. if he's eating ect I would just leave it if it was my fish. It's one of those situations where intervention may be more dangerous then just leaving it be.
I think that he have problems to eat...

[video=youtube;4bJmd14rXco]http://www.youtube.com/watch?v=4bJmd14rXco[/video]

