In order to remove a team member, you will go to the Design Collaboration Module using the module selector on the top left of the screen. Choose "Settings" in the menu on the left side. Choose the "Team Setup" tab on top of the screen. You should see your list of teams here, click on the number under the Members column for the team you need to remove someone from. Here click the "Remove" button next to that person's name. You can see this button at 2:51 in this video.