Here are 3 examples that you can use for resignation letter as Assistant Professor -. Resignation letters should use the formal greeting: "Dear".The first sentence in the letter should state that you are resigning and when. This is to inform you of my intention to resign. My last day of work will be (DATE). An exempt monthly-paid staff member is expected to give at least four (4) weeks notice. Notice should be in writing. I am writing to formally tender my resignation from my position as an Assistant Professor at Crestwood High School, effective June 20, 2053. Include the position title and the last day you intend to work. PURPOSE: To outline the amount of notice a faculty or staff member should typically give when submitting a resignation or retirement.