This form is available here for download. Fill out and file in duplicate Form 424, Certificate of Amendment.Learn how to file an amendment for LLC or corporation formation documents in Texas with our free guide and filing instructions. Making a business amendment to an LLC or corporation usually requires Articles of Amendment. Learn about this document and how to file it. The first step is to file a form called the Certificate of Amendment with the Secretary of State and wait for it to be approved. The attached form may be used for filing articles of amendment for a limited liability company. Submit the form to the state and pay the filling fee ; 4. While forming an LLC in Texas, you must file the formation document. After completing the correct form, it's simply a matter of submitting your amendment and the filing fee to the appropriate state agency.