To change a registrant's team, follow these steps below :
1) Go to campaigns admin panel.
2) Click on the People tab and Registrants tab under it.
3) Find the registrant from the list and click/dbl-click on the record.
4) Click the Edit button on the pop-up.
5) Scroll down to "Team Info" section.
6) In the team field dropdown select the team the registrant is to be placed in.
7) Click Save button to save the changes.
8) Refresh the registrant's page to see the updated team.