Use it to buy mining equipment and build a good mining system and get alternative coins from doing it. You will have enough time to trade it for bitcoin. And after two month you will make at least 1 bitcoin if not more doing it. If you pick the right alt coin to mine that is.
At least that is what I would do to make sure I don't lose out on any investments that could go bad within that two month 7 day time frame you have to pay it back to your friend.