Take a dump on his doorstep.
Man the **** up. Call the police/council/who ever he rents from.
Let the police know that he has threatened you with a knife.
By loads of Sunday papers, take the trash mailings out for hearing aids, butt plugs etc and fill them in using his address but with a selection of cleverly masked abusive names. Wait a few days and wait for the torrents of junkmail with annoying names to constantly flood his letter box.
Then move.
Let the police know that he has threatened you with a knife.