Rough Drafting...Rough concept

Well I must admit that I have been rereading my rough draft many times trying to figure out how to make "substantial revisions". I'm completely at a lost. I have 5 sources and in my opinion have met the criteria for the final project in what was completed in my rough draft. Generally the rough draft is mainly the final project, except with any changes suggested after review. My rough draft paper received good marks so now I am sitting here thinking to myself how am I supposed to fix what's not broken???? So confused!