As you will now have realised, the Qualifying Cross Country section is organised between yourself and your instructor so a different setup than the General Skills Test which is with an examiner. You should prepare the navigation in the way you were taught by your instructor (using whatever method was taught), going on a route which would be discussed with your instructor (how detailed that discussion is will depend on the instructor).
You'll get your instructor to fill in the section at the top, print off and sign this form:
http://www.caa.co.uk/docs/33/SRG2105FF.pdf
You will then take that form with you and get it signed where you land. When you return, your instructor will sign the bottom if he is happy.
At least - thats how I think it goes (I'm preparing for mine at the moment...)