Simply start a franchise and pick any team. Make sure you turn off the salary cap. After simming through the entire season advance to the off-season option. After simming through the retired players, resigning players, and the NFL combine sections of the off-season, the free agent bidding will start. Simply bid on the top 6 teams by pressing A. Keep pressing A when another team outbids you. Wait 60-70 seconds for the countdown to finish and you will unlock the achievement. Takes roughly 8 minutes from start to finish. Enjoy!