Legal Question in Wills and Trusts in California

First, sounds like a probate petition has not been filed to probate the estate of your mother into your names. That being said, obtain the assistance of a probate legal counsel, who can file a petition intoi probate court to obtain a distribution of the title into all of your names, and tthen compel a sale of the residence with a division of the proceeds; You will want to back charge your brother for the reasonable rental value of the house since the date of death of decedent which could be charged against his share of the estate. Don't delay.

Mr. Waid is correct in that you'll need the authority first--if it's a trust, is the successor trustee in place? If so, the trustee has the authority to evict him and sell the house. If your mother had a will, or no will, probate is required--once the executor/administrator is appointed they have the authority to evict him and sell the house.

If the house is already in you and your siblings' names, you can file a partition action to force the sale of the property.

You need to speak to a competent probate attorney as soon as possible. It sounds as though this property was either in a trust, or was to pass to someone by a will. The longer you wait, the worse this situation will get.