Easiest way to do it ; grab a buddy , checkpoint battle with the song jump around , which only has 5 - 6 checkpoints , one of you guys goes first by ranking up 10 wins then switching over ; the song is short 2:22 , so 10 wins plus the time added trying to find each other online ** if it got crowded ** lol bout 45 mins / 1 hr and a half for both people ( 10 wins each )
so it the end ; 3 hrs of some good scratching , could pull off 20 wins each with some kick ass DJP lol again this method could go towards playing 30 xbox live battles online achievement
I hope this helps :)
good luck and hope this helps :)