Two Controller Solution:
From the Main Menu go to Features / Settings and make sure game difficulty is set to All Star. Go ahead and change quarter length to 1 Minute if you really want to fly through this.
Now go back to the Main Menu and choose Play Now, then Quick Play. From Current NBA Teams, choose Team Joel or Team LeBron. Now load up a second controller and choose the opposite of the team you picked and start the game.
Simply win with your main profile to unlock the achievement, it'll unlock the moment the game ends.