First you must choose between buying a new car and buying a used car. Complete Forms: Fill out the Application for Texas Title and ensure accuracy.Key documents required for title transfer include the original title, a bill of sale, and valid identification. You'll need to sign the car purchase agreement (or dealer bill of sale), the title, an odometer statement, and sometimes a damage disclosure statement. Edit, sign, and share vehicle purchase agreement online. No need to install software, just go to DocHub, and sign up instantly and for free. Step 1: Write the seller's full name on the bill of sale. Use the legal name that the DMV will have on record. When buying a vehicle or equipment for your business, use this Vehicle and Equipment Purchase Agreement to protect yourself from unwarranted liabilities.