Thank you for your question
My name is ***** ***** I shall do my best to help you.
You need to give him "reasonable written notice to leave " two weeks would be reasonable.
At the end of that time pack up his belongings and change the locks (get your landlords permission) and call the police if he attempts to re-enter the property.
If in the mean time he is violent then call the police immediately
Please ask if you need further details