Let's dive into some of the FSBO paperwork that will be necessary when legally selling a house without an agent's help. This FSBO paperwork is needed as soon as you accept an offer, so it's useful to have a purchase agreement onhand that you can fill out quickly.Know the documents that you need to sell your house on your own in Texas. A Texas residential purchase agreement outlines the terms and conditions of an offer to purchase real estate. Step 2: Fill out your disclosure forms. No need to install software, just go to DocHub, and sign up instantly and for free.