Another person lent me $200k towards a down payment to purchase a home. To protect their the loan they asked to be added as tenants in common on the deed and note. I now have the money to pay back t

What is your question?

I think you will probably need to seek the advice and services of a real estate attorney and perhaps a tax attorney in your state to change the deed. It might be treated as a sale of the other person's interest or it might be the repayment of a loan. That is a not-obvious thing for the lawyers to figure out.

That is why most security for most loan are done by recording a mortgage lien on the property and not by sharing ownership. That way the lender is protected (you can't see without satisfying the lien) and you don't have to worry about your lender selling the house out from you at any moment. (Any co-owner has an absolute right to "partition" the property and order is sold.)