1. Go to Edit mode.
2. Players.
3. Create player.
4. Select where you want to base copy player: created players 1, 2, 3, 4 or 5.
5. Pick a "unregistered" slot.
6. Select "base copy", the option in the bottom.
7. Click next.
8. Select the team where the player you want to copy plays.
9. Select...