Request a demotion by drafting a formal letter to your supervisor or manager explaining your desire to alter your current position, providing clear reasons for the request while assuring her that you can continue to work effectively in a lower position. Give the letter to the supervisor during a meeting between the two of you, in which you may discuss the matter and make plans for the transition.
The process for requesting a demotion requires a combination of official documentation and personal reasoning to ensure that you are able to step down from your current role while continuing to work within the company. Begin by writing a letter to your supervisor officially requesting that you move out of your current role and into one with fewer responsibilities or different requirements, citing a specific job you wish to take instead if possible. Offer an explanation for why you are unable to perform your duties, such as personal or medical reasons.
Schedule a time to meet with your supervisor when both of you are free to discuss the matter without interruptions. Provide your supervisor with the letter, and explain that you do not wish to quit the company but that you feel you can better serve it by taking a different position. You may need to work out a plan to carry out your current responsibilities until she finds a replacement.