Briefly explain the reason for your letter by telling the reader what the assignment was and that you feel the grade was inappropriate. Include the course information, such as the instructor's name, the course name, number and section.
Explain why you believe the grade you received did not fit the completed assignment. Cite any grading criteria in the syllabus supporting your claims. You may also choose to quote statements made by the instructor during class regarding grading criteria.
Include any dates and times you discussed the grade with your instructor and include his responses. If the grade was discussed via email include copies of all emails.
Enclose copies of any documents supporting your claim. Your syllabus, graded tests, graded assignments and statements from other students may be appropriate depending on the situation.
Locate the correct department for grade appeals. Often this department is called the Department of Grievances, however, the name varies among universities. The information should be listed on the school's website, but any department office should be able to direct you.
Send or hand deliver the letter to the appropriate department and to your instructor. If you mail the letter, send it certified with return receipt requested.