Okay I will try to help you! In the settings mode or customization you will find a thing that says download rosters... I think this is where you can download offline rosters for GM,season mode etc. Although im not sure if its for this or if someone wanted to play with a diffferent roster.. But if you really wanted to make all the roster changes you could trade for them just like in real life and I know this would be a waste of time! Hope this helped please leave an xp if it did!
