My Mom owns a home in IA but is now living in assisted living in MN .What state do we file for guardianship and how?

We have POA durable power. My mom has alzheimers. We have document from doctor stating that she need 24 hour care and she is not making wise decisions. She own a home in Ames, IA house is in her name but my brother who is 50 has been living there and my mom has been supporting him for years. We need to sell the house, we do have POA and durable power. But we don't know what state we need to file for guardianship and conservership. Or if what we need that so we can sell her home and evict my brother. We want to go to Iowa and get some of her furniture but brother change locks and doesn't want his mom to have her good furniture and leave him with the old worn furniture. He is a felon and drinks and smoke in the home as my mom has COPD and has been told to smoke out- sideand he just laughs says she has a good heart. My brother has brain wash my mom stating all we want is the money, but in reality he doesn't have a place to move to and he wants to stay there and have mom pay ultitles which she can not afford to do. If you could tell what state and what we need to do to make it legal we would appreciate it.