But, you will need to log back in to this team after you've created your new team, and it should prompt you to choose which team you'd like to keep as your free team. Choose your new team. This will permanently lock you out of this team, though.
I can tell you! Just go to account settings, and under "general settings" at the bottom-right corner of the box click "cancel account". Then you can create a new team once this team is gone.