I need advice on how to do a lease option assignment

[Schnell Manson]

I am new to REI and I have found a motivated seller but I am not sure if the numbers work.

It is a 3 bedroom 2 bath 1,565 sq ft house built in 1976. The seller owes $85k on the mortgage but the after repair value is only about $45k. The house needs some cosmetic repairs ($3k to $5k). Their monthly payment is $688. They previously had a tenant paying $900 (person moved out in July).

Given the numbers above, is a lease purchase option feasible with an investor? If so, how do I setup the contract? This would be an assignment transaction.

Any guidance is appreciated.