Want to evict family members from household but they said "we're not leaving"

Location: Los Angeles

So unfortunately, about 10 years ago, my direct family decided to have my parent's family move in to our home. Two currently still live here. My parent is paying off the house and my grandfather is informally paying rent. My uncle is the other family member and he doesn't pay anything. He just exists here and creates problems.

We want them out now. We've talked to them about it and basically they said they're not leaving. What can we do? We want them out of here.