In this article, we share tips for writing a short, simple resignation letter and offer examples for you to reference when creating your own. Below is a sample union resignation letter.You should check your union's constitution and bylaws to see if it is specific to whom a resignation must be sent. Then, state your intent to resign and exact date of departure. Learn how to write a professional resignation letter with our step-by-step guide, easy to use templates and helpful tips. Stay in the know with the latest Albuquerque news. From the top local and national stories to the latest Albuquerque weather, KOAT has you covered.