what all documents needed for converting H4 to F1 visa?

Hi, I am on H 4 visa now…I took a course on H4 in USA…Now , I want to do my intern and get certification on F1 visa so that later I can use my F1 visa to work in a school by applying for an OPT…

I am going to apply for F1 this month… I need all documents in detail and also would like to know" what reason should i give in a letter for conversion"…i took I- 20 from my institution…please do give the latest updates about the F1 documents to be submit…

hope to get responses asap…thank you!