Hi, I had this problem for a year. My “trainer” would enter her paddock with a treat and catch her. I DO NOT recommend this. She sometimes would take the treat and then run away, teaching her nothing.
Here’s a sure fire way to fix this bad habit.
Always enter your horse’s area with a lunge whip while you are changing this behavior. The moment he starts to move away from you and/or turn his butt to you chase him away. Then verbally tell him to come to you and turn his face to you. If he doesn’t then chase him away again. If he threatens to kick, smack him hard on the butt. It takes approx. a month to change a habit. Always be ready with your whip during this reprogramming time period. Soon he will find it enjoyable to come to you and be haltered. THEN you can give him a treat. But only after he allows you to halter him. Also a really great reward is your voice telling him what a good boy he is and a scratch on the neck or withers. Horses are very in tune to the tone of your voice. Good luck with him! Cheryl