How do I move players and staff between teams?
Go to Rookie Me Hub
Go to the menu on the left hand side of and select Team participants.

Players (and Staff) can be copied to new teams.
They can also be archived from their existing team (or be left there and remain in two (or more teams).
When you are starting new year you can easily copy existing Players (and Staff) to your new team(s) and bring all of their historical data with them.