How would you make this deal work with no money down?

[Jesse Ramirez]

I have an owner with a free and clear home who is looking to sell.
The home is a fixer going for 80,000. Home needs aboout 20,000 in work and it's ARV would be 130,000 based on comps. The owner wants 30,000 down.
I was going to ask him to pull a new first for 50,000 and carry a 2nd for 50,000. From the 1st he pulls out 20,000 would go back to me as a credit for repairs.
This is my first time playing with this approach and was just wondering how I would make this work legally. Do I just go to a title company and have them record everything? Do I just write up a contract on my own?