My horse did the exact same thing. Once he starts moving it (because he swings it, right?), growl, and then if he puts it down then give a good hard smack on his belly(I said shoulder last time but belly is better) and yell/growl "no". Pick it up again, if he doesn't pick it up, growl(warning, I think you know what I mean by growl as deepen your voice sort of) and then if he still doesn't pick it up give a good hard smack on his belly. It would be better to to a session of ground work to show your dominance before you start with the hooves so he is aware that you are in charge.