So this is a very late guide. But now with backwards compatibility this is very easy if you have 2 xbox live profiles. You can play with one person on the Xbox 360 and one person on the Xbox 1. Just set up a game with 2 people maximum and put both of the profiles in the game (which isn't hard because no one is on the servers anymore). Pick your best character with the profile you want to win and the worst character with the profile you don't want to win with. Pick melee and win. To do this 40 times it takes 20 minutes to half an hour. Cheerio
EDIT: Thanks to PrinceRules64
you can also do this if you don't own 2 gold accounts just read below!