How to write a resignation letter that's effective immediately? Welcome to Chicago Resume Expert for Resignation Letter Writing.Many times it is difficult to resign diplomatically and tactfully. Learn how to write a professional resignation letter with our stepbystep guide including 15 resignation letter examples for various situations. Remember to leave the company on good terms, starting with a 2 week notice letter. We've got you covered, from tips to samples. This letter should specify your last day of work. Your department will forward a copy to the Human Resources Department for placement in your personnel file. The Shared Services Office is responsible for verifying documentation such as resignation letters and approving exits in the HR system. It is time for Chicago's newspaper editorial boards to call for Mayor Brandon Johnson's resignation.