I am an RN with a BSN and I instructed CNA's last year while in VA (licensed in TX--worked with reciprocity). I simply contacted the Board of Nursing in Virginia and submitted a form through my employer. Contact the Board of Nurse Examiners for the State of Texas. It is easy to find on a google search. They will have the legal information you need to ensure that you meet the qualifications for teaching in a state approved CNA program.