seller financing analysis

[Varinder Kumar]

An acquaintance of mine recently lost her mother and was left her home how ever her brother and her now have the house and her brother wants to live in the home so he would have to buy her out. The home is paid off. I am yet to receive the address from her to check all the number on it. My question is, I would like to structure a seller financing deal with them for 30 year interest only payments with no money down. However since there are two people involved how can I structure this if they both agree to it? 
I add both of them onto the contract and they both get 50/50 of the monthly payment from me? Or is there anything else I can do to obtain this property. Thank you