Yep, what Ariana said...lean into him with your body when trying to lift his hoof, he will lift his foot to regain balance, then just stop leaning into him when you have his hoof. He’ll eventually learn!
My mare struggled with thrush when I first got her. She was picky about her feet for a while and it helped for me to just pick her hoof up and hold it and not treat or do anything to it. So she got used to them being handled. so everytime I went for it she didn’t think I was going to treat it or clean it out. Now she could care less
You can try pushing with your shoulder into his body above the hoof you want to pick up. If that doesn’t work, try making him take a step and pick it up as he picks it up it walk, obviously if he freaks out drop it carefully so you or him don’t get hurt!
Hopefully this helps! :)