1, I-539 form
2, a Letter form your school with explain
3, a letter from you, tell the reason, what is your grade and so on. let officer know you are good student.
4, new I-20 and all of old I -20s.
5, get new term tuition receipt and all of your transcripts.
all letter should be professional, you need dress up and good oral... Let them know that is northing, have to reinstatement. Good luck.