If you have already created the team, 

  1. Click on the edit button for the Team
  2. This will open up the slide-out panel
  3. Go to the bottom of this panel, and you will see a field that says, players
  4. Select the players for the team
  5. Click save


If you haven't created a team,

  1. First, click on the 'Create a Team' button
  2. Fill in all the details for the team
  3. Then follow step 3 in the above list