Either way, this all starts with ground work. Take the time to let him graze. Go for nice walks with him, do a lot of bonding things, but also work on keeping him out of your space and make sure he respects your personal space. With feeding, as you approach his stall make sure you pay attention to his ears and where his focus is. If at any point he takes an ear away from you (you want both ears forward) or he looks away from you STOP. If as you approach he pins his ears STOP. Wait until his ears are forward and/or his expression softens. When you get to his stall DO NOT go in. That is his personal space, his bedroom, and you need permission to enter. If he does not approach you just wait, relaxed body language, energy turned off of him (but still watching him!). If he tries to approach with a nasty look take a lead rope and drive him back. You don't have to be mean or aggressive, just stay calm and drive him back. He is not allowed in until he has a nice look on his face. If he turns his butt to you take the lead rope and lightly flick him on the gaskin, but make sure you are out of kick range. You don't want to smack him, just irritate him enough to that he turns and gives you his attention again. When he gives you permission to come in (ears forward, nice expression) enter the stall, put the food down, and invite him in. If he gets nasty drive him back. If he is nice resist the urge to touch him. Just leave the stall. Through this whole exercise you are showing him "Look, I'm alpha here, but that doesn't mean you can be ugly and that doesn't mean you have to be afraid. I respect your space and thresholds but in turn you have to respect my space."
Be prepared for this to take time. Be patient and consistant. It will work, you just have to take the time it takes.