I doubt that a court would rescind an order of protection based on a letter request. It would seem to me that there must be some court proceeding in order for an application to be made to undo a previously-ordered order of protection. It should also be noted that you should not seek to engage in an ex parte communication with the judge; that is, to communicate with a court without a copy being delivered to the other interested parties (i.e., the person who obtained the order of protection or, if represented by counsel, that person's attorney).
Please note that I am a New York attorney and cannot advise you as to the application of your state's laws. For that reason, you may wish to consult with a local attorney.
Good luck to you.