Family Law Questions? Ask a Family Lawyer Online.
The theory of divorcing from ones family seems easy.....in reality it is not. Since you are no way required to have a relationship with siblings and are not required to allow them to inherited from you the courts often dismiss these petitions. The will cost you far more then it is worth in the end. Most judges dismiss these cases before they are even heard and term them as frivolous based on the fact that you can choose to not have contact with them.
In your situation, all you need to do is cease contact. Let them know to not contact you any longer and if they continue you can get a no contact order from the police or local courts. You will want to make sure that you add a stipulation in your will disinheriting them and why to prevent any issues with them trying to contest the will.
I wish you the best,