Seller Financing with an existing mortgage (Wrap Mortgage)?

[Cody Sizemore]

I have a property that I am interesting in purchasing, and I have a good relationship with the sellers. I'm considering doing seller financing due to the higher interest rates right now, but they currently have an existing mortgage on it. 

Property sale price is $100k, mortgage is about $60k. How can I legally purchase the house using seller financing, or a wrap around mortgage and set it up so that I come out with the best case scenario?