Buying first home with seller financing

[Nick Miller]

Hello BP community,  

Looking to buy my first rental property. My uncle has a property that has one tenant upstairs already paying $700 a month and could rent the downstairs after some painting and light renovations for another $750.  My question for the community is how should I go about buying it from my uncle as I would like to have him do seller financing. How would I go about making that contract? He is looking to sell it to me for 100k, when after renovations and market value is about 125K. I would like to offer him to do seller finance but give it to me at a lower price like 90k, so that after interest he would get 120kish. Thoughts?