You can easily remove participants before, during or after a challenge.
1. To remove a participant from the Org, go to the Group they are currently in, and select them by clicking the check box to the left of their name/icon.
2. Click the trash can icon in participant's row, or click the Delete button in the top right corner of the Group box.
Note: You can delete more than one participant at a time. The participant will be able to re-enter the Org at any time with the Org Key if the Admin settings allow new participants to join the Org.