Org or call 972-925-4300. This job aid describes the process for submitting your resignation letter.Thank you for your service to the public at the City of Dallas. This page contains information as you leave your employment with the City. In the body of the letter, state your intended retirement date (your last day) and your thoughts on a transition plan. Resignation is effective as of the date indicated on your S-54 form. Resignations are processed as final and do not continue to pay out over the 12-month cycle. How do you write a retirement resignation letter? Dear (Manager's Name):. Submit a retirement or resignation letter at Human Resources.