You can combine this with the legacy achievements if you like. My walkthrough for it is included in the linked achievement.
Download my "49ERSLEGACY" 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.
If you do want the 8 legacy achievements as well (and 1 misc. achievement), follow the link first. Thereafter, be sure to then go to league settings in the Franchise menu, and change your Season Experience setting back to Full Control. Then simulate to the nearest off-season.
At this point, you should see a prompt on your home page in the franchise page (under things to do, I think) to re-sign players. Virtually all players will be 90+. Re-sign any one of them to unlock the achievement.