Now that you know what you're really arguing, work on the introduction and conclusion. Has the writer avoided insulting the reader? If you were presenting to a crowd, would it be well received or is something still missing?
Does every paragraph address the subject matter of the thesis in some way? Is the topic too big or too narrow? There is no point finding and correcting all of the grammatical errors if you have to rewrite the entire paper because of problems with the strategy toward the audience.
Consider connections between and among ideas. In fact, any of them revise their work multiple times before considering it to be complete. The New St. Revising your essay is a multi-faceted process.
Your task should be free of those since some can change the meaning of your text. Is the documentation in the Works Cited page and body of the essay correct?