Hi jmoxx,
I agree with what the others have said.
Without saying too much, as long as you have a general knowledge of aviation, gained from reading and understanding the document they sent you, you'll be fine.
There were 1 or 2 questions also outside the scope of what is in the motivation document, again I guess to test your general understanding of aviation.
I found the paper easy enough. Just worry about the cubes and diagramming!