Tex. Est. Code § 1104.054
(b) Notwithstanding any other provision of this subchapter, a minor at least 12 years of age may select another guardian of the minor's person or estate, or both, if the minor has a guardian appointed by the court, by will of the minor's parent, or by written declaration of the minor's parent, and that guardian dies, resigns, or is removed from guardianship. The minor must make the selection by filing an application in open court in person or by an attorney. The court shall make the appointment and revoke the letters of guardianship of the former guardian if the court is satisfied that:
Added by Acts 2011, 82nd Leg., R.S., Ch. 823 (H.B. 2759), Sec. 1.02, eff. January 1, 2014.