I have never heard of someone disowning a sibling.
You are free, I suppose, to have nothing to do with him, to issue notices against trespass with respect to property in which you are the person in lawful position, and if you are afraid of imminent harm to your person, to obtain a restraining order or other similar judicial relief to keep him away from you. But he's your brother, violent, vindictive, and mentally ill though he may be, and he will ALWAYS be your brother no matter what you do.
Not legal advice, just my two cents based on general principles of law. I don't practice law in Oklahoma or hold Oklahoma licensure. If you need legal advice, please consult a lawyer who holds Oklahoma licensure. I practice in Vermont ONLY.