No. Under no circumstance should a real estate license holder attempt to prepare a lease-purchase agreement. Since there is no lease-purchase agreement form for license holders to use that complies with the Real Estate License Act requirements, an attorney must prepare the agreement.
Preparing your own document or changing a lease-purchase agreement prepared by an attorney for another transaction is a violation of the Real Estate License Act. Taking such action is the unauthorized practice of law. In addition, there’s a risk you could be sued by the parties if they have a disagreement over the lease-purchase agreement you prepared.
The requirements of the Texas Property Code provisions that apply to lease-purchase transactions are complicated, and your client shouldn’t enter into one without talking to a real estate attorney.