Request Letter to change classes

Dear Sir/ Ma'am! I am task to write a letter to our school principal requesting that a change of class be granted. You see our children are enrolled in a Science school thus we deemed it important that instead of our children taking the Advance English class in their senior year as part of the curriculum for the special journalism class, we would like to request that they be allowed to take the Advance Chemistry class just like the other regular senior sections. Since we are enrolled in a Science school we should put precedence over taking Science subjects than that of English subjects since we believe our classes in Journalism and English IV should more than compensate for the Advance English class that were assigned. Moreover, most of our children are geared towards taking Engineering and Medical Allied courses in college and of which an Advance Chemistry class in senior high would be of a great advantage and use. We, would also like to attach to this letter a signature campaign letter wherein all the parents of our section would sign as proof of agreement to above request. Hope you can help me with this. Thank you so much