i think the important thing is to give him a realistic deadline. sit down n a conversation - tell him he has to move out and negotiate a date - stick to it - help him etc.
tell him he is always welcome in your home and you love him, but he needs to move out now. he has til [i would suggest] end of february.
i found one my son moved out to work at butlins for the summer,homelife was a lot easier.
perhaps try butlins or keycamp type holidays.
YOU must tell him firmly that although you love him very much, you will have no hesitation in calling the police if he threatens you again. tell him you wouldnt allow a stranger to do it - and remind him that he probably wouldn't eaither.
tell him if anything happens to your belongings or car - he will be arrested and afterwards your brothers will knock his head off. - them smile and tell him you love him, but you require to be treated with a certain amount of respect by anone - just becuase they are human - not becuase they are mother.
love you son, you have til end of feb, you will always be welcome back here for visits and chats and i look forward to it - i will help you out with a deposit. however if anything happens to me , your sister or any ofour belongings , i will call the police - and i am not kidding. when they are done with you and your community service or whatever sentence then uncles will wrap your arse round a lampost. so, behave yourself love, and iwill help with a deposit, i love you - but its time.