How to get back at this pr**k?

we used to be friends, like ageeeeees ago. i actually hate him now. he is completely making my life absolute hell. he says the worst possible things to me AND he is turning ALLLL of my friends against me.i really cant explain in more detail right now because i am so angry right now but please dont ask me why he's angry at me or any other questions just tell me how i can get back at him. if you have anything else to say then dont say t cause i swear i am this close to chopping off someones head and whoever isnt on my side right now i will just go even crazier. any ideas?