My gelding has an issue with his feet (his abuser would whip the heck out of his feet to get him to move back), so we've just started over from the beginning.
Take it slow, and make sure you rub down his legs every day. Once he's comfortable with you rubbing down his legs, ask him to pick them up, but don't push him too fast. Just ask a couple of times, and pat him and tell him he's a good boy.
Once you have that down, start asking more until he begins to give to the pressure. Eventually he'll lift is foot a little. Don't force him to keep it up, just let him lift it up and put it back down and praise him like he won the Derby.
It may take a while, and we're still working with our gelding. He's to the point that he doesn't try to kick us anymore.
Oh, also, make sure he's squared up on all fours before attempting to lift them.
I hope that works for you!