Can a sibling being evicted from deceased parents home?

First of all, my mother and father did not have a will. There are six siblings and two of them live in the house. My brother is addicted to drugs and the living conditions for a child or anyone is impossible. My sister and her eight year old son has been sleeping on my couch for the last week. I've been helping with the bills myself and last night I tried to talk to him but he went nuts on me calling me names and everything. He had other addicts there, he eats the kids food, and doesn't contribute financially. The problem is that we want to keep the house so my sister, who suffers from epilepsy, has a place to live. Can we evict him and keep the house? Letting it go is not the answer I want to hear. I want to take the necessary steps to become executor and get him out, if possible.