In outlining this paper, there is a very specific structure that must be followed to achieve top marks. First, introduce your topic, setting out the 5 areas you plan to discuss. Then have a paragraph (or two) for each of the five topics: audience, content, tone, style, and structure. Context is equally important, I suggest that you include details about this in your introduction as it lays a good foundation for your writing.
For each topic, you should evaluae the differences and similarities within the text. There are two ways to do this. (1) You can first target the "Big 5" concepts for text one, then do text two, and then compare. (2) Or you can evaluate and compare each text in reguard to content, then structure, and so on. Either way is acceptable.