To get a sealing canceled you must put in writing ALL your sins since your previous marriage. Even if repented of.To leave the Church membership, write a short letter to your bishop and ask that your name be removed from the membership records. This chapter is organized to guide leaders through the key decisions and actions necessary to help someone repent of a serious sin and to help protect others. The LDS Church has tightened rules on people using QuitMormon to resign their membership. Find the email you received when you signed up to usher. It is titled "Sign Up Confirmation - Usher" (if you need to google it to find it). There are 2 forms: one for after shares are issued and one for prior to shares being issued. On this site you will find a sample resignation letter. When you resign, you can use that letter exactly as it is, you can edit it to fit your own tastes.