You need to win an event after you have gained your PGA tour card. The first event you can get this on is the Bioware Classic. This is a fairly easy tournament to win and should be possible by doing all 4 rounds in the 'quick round' format rather than full rounds. If you find you've completed 2/3 rounds and you don't think you're going to win change to full rounds to give yourself a better chance at getting a good score. (The option to change is under 'Career History' > 'Round Type')