you don't really need more than a letter along these lines: according to the terms of our month-to-month lease agreement, we are hereby giving you formal 30 days notice of termination of the lease. By (date) we expect you to have vacated the premises at (address). If you have not vacated by that date, we will begin formal eviction proceedings.
do this after they've paid the rent (or else they'll probably not pay) and make sure 30 days' notice is what's required in TX. Hope you don't have to evict, but if so, do it by the book to avoid being sued.
Jan 22, 2010