I stay in a joint family. My maternal elder uncle marriages are not good. First marriage is divorced

I stay in a joint family. My maternal elder uncle marriages are not good. First marriage is divorced, second marriage is also divorced, thrid marriage the person died by suicide, he won the case in court., and he is in living relationship with 4th female. He is trying to mingle 4th person into the family but we are not willing to as she is dominating and disturbing our normal daily life and judging our actions. We are friendly to his first wife as she a kid and is longer associated with our family for 7 years...my mom and she are friends after divorce. nThe 4th lady is not satisfied with this and is trying to rule us indirectly and causing issues. My uncle is giving warning to leave home if we had ties with the first wife.My grand parents are old aged and grand mother is cancer patient and is in her last days. This is causing too much drama. How can we permanently get rid of my uncle ( we don't want any ties with him) and the 4th female legally?