A good way to get a horse to learn to pick up their feet is by putting a lead around the fetlock and gently pull the lead towards the front of the horse until they lift their foot slightly and once they pick it up a couple inches set it down instantly, but don't drop it. Do the same thing with front and back feet a few times. Once he's used to that then you need to try lifting higher, till the hoof is high enough you would normally be able to pick it out, then set it down. Then move onto holding it up. Then you can try picking it out. If he leans on you, the second he starts putting weight on your shoulder DROP his hoof. That's how I taught many horses to pick up their feet, and the good thing is they can't really kick you while you are at a distance with the lead rope.