First, win against the Very Hard AI, Hard AI, and the Very Easy AI, that will give you 3 of the 5.
Play against yourself with 2 players, then play a word or 2 with P1 and then just keep passing with both players. That will concede the match and you'll win.
NOTE: the 7 tiles in your hand will be subtracted from your total so make sure you have more points than that total otherwise it will just tie.