How do I complete a sale or lease option?

I have a property that I am buying subject to existing mortgage and i have a buyer lined up. i don’t know what to do to sell by owner finance. in the state of texas it seems like you can not use land contract if there is an existing mortgage. do i use a wrap instead? what about lease option? i heard texas real estate law calls that a sale. do i need to sign two seperate agreements? one for lease and one for purchase? also what needs to be held by escrow company and recorded with county if anything? i would appreciate the help. i have found lots of information in the forms on how to acquire the property and the details involved but not much on selling the property and the details involved. any good books or courses out there? :banghead

What is wrong with a traditional sale?

Traditional Sale? like put it on the market? this property has almost 0 equity. I want to owner finance this property after i have taken subject to. The problem is i don’t know how to collect downpayment from my buyer nor do i know the details of selling to them using owner financing. Rents in the area are 1100 and the seller has a payment of 1000 piti. my buyer could pay 1200 piti.