Tell your friend to take a chill pill. Then calculate how much work you did and what you think you should be paid for it. Give back anything over that amount an

Tell your friend to take a chill pill. Then calculate how much work you did and what you think you should be paid for it. Give back anything over that amount and give him all the files you worked on. Then move on. If you're honest with yourself, it will seem reasonable to a judge. Above all, stay classy.