Renewing CNA cert. in TX

Hi all! I can't seem to find this information anywhere... I received my CNA certification in March 2008 and worked at a home health agency with it from February 2008 to December 2008. My cert. expires in March 2010 and I really want to keep it in case I decide I want to work with it again next year. How would I go about renewing it?

Thanks so much!