Brother came back to live with parents after 20 years how to vacate

We were joint family and story is similar of Baghbaan.One of brother who was staying with his family away since almost 20 years came back with us and we asked to stay for a while and start looking for there own house.It's been 6 months and still they are here and every now and then new drama they create and fight happens.My mom and dad are senior citizens and very weak,I'm in worried all the time if something happens to them and goes wrong,it keeps me worried all the time.We are not able to stay freely coz of them.I need advise if a legal notice can be sent to them without going to court coz we don't want to run in court for this matter and ask them to vacate maximum within a months time and until they are staying,they have to stay calmly and should not raise there voice to anyone in the family or demand anything from us coz since last 20 years they never cared for us.They need to leave asap and until then,then can stay but without creating any scenes and noises in the house.AdviseASAP