You'll probably earn this naturally by just playing the game. However, if you want to speed the process up a bit you can go and edit player attributes and make it so the players on the other team have 0 plate discipline, 0 contact, and 0 power. Make sure to boost your starting pitchers attributes as well. Then head into play now, making sure that you have the edited roster loaded, then choose the home team so that you get to pitch first and just restart the game if you don't get it in the first 3 batters of the game.
Also don't forget to raise and lower human pitching and AI hitting sliders to make it a lot easier.