This one is easy, but you'll need a boosting partner or a backup console with a dummy account and EA Access (trial or cheap 1 month). I recommend you follow my walkthrough for Bragging Rights, as you'll get this and Head-to-Head with ease.Download my "49ERSLEGACY" or "49ERSLEGACY2" roster from the community files section of the settings menu, then load it up in the share & manage files section of the settings menu. Then start a cloud franchise.
Set up the league with 1 min quarters and accelerated Play Clock for the quickest time. If you have a friend, invite them to your league now. If you have a 2nd console, just make a dummy account, and invite them to the league. This way is easiest as you're good to go without boosting with a real person.
Now ensure your boosting partner/dummy account selects the
Buccaneers (1st game on the 49ers schedule). Now all you need to do is play the 49ers vs Buccaneers match with your friend or dummy account/console and win.