You can file a contempt motion for violating the divorce decree.
This response is intended to be a general statement of law that should not be relied upon as legal advice and does not create an attorney/client relationship.
I suggest you consult with a local family lawyer. You may have only a breach of contract suit against him, and attorney's fees are often not assessed until the end of the suit.
You should contact a local family attorney for a consultation. Oftentimes, attorneys send out letters requesting compliance or court intervention in which they will charge an hourly fee. If he does not cooperate, then you can either move forward with filing a motion for contempt on your own or hire the same attorney to pursue contempt.
Actually, this part of the divorce decree is contractual in nature, and is likely not enforceable by contempt in Texas, as it is prospective and probably not of the required specificity required for a quasi-criminal proceeding like contempt. You can, however, sue for performance of the contractual obligations imposed by the decree, and you can seek award of attorney's fees and costs for such enforcement.