You have a complex situation which requires you to hire an eviction attorney to ascertain the best legal strategy to achieve your desired goal. It is not just a matter of giving you the correct Civil Code section.
Frank W. Chen has been licensed to practice law in California since 1988. The information presented here is general in nature and is not intended, nor should be construed, as legal advice. This posting does not create any attorney-client relationship with the author. For specific advice about your particular situation, consult your own attorney.
You need to formally evict your brother. I handle evictions. Feel free to call me for a free consultation.