Step Seven: When she enters the room pretend to be unconscious. Allow her to turn you over and try to wake you for a few seconds before you open your eyes. The injuries to your body will serve as a distraction to your nakedness. She will be more concerned about your wellbeing instead of fearing the naked man in her room.
…
Step Ten: If your friend is a curious person she will probably ask ‘What worked?’, even if she doesn’t ask this question it is important that you now say the words ‘(Insert Friend’s Name), I’m from the future’ in your most deadpan voice.
Step Eleven: Pause for ten seconds to allow the incrediblness of the situation to sink in. There will be no reason for her to doubt your claim, because your beard will make you appear many years older and your cuts would add weight to the idea that you’ve come from a post-apocalyptic future where a war is currently taking place.
Brilliant!