At your school you may have decided that only the Loops administrator at your school has the authority to remove students from Loops. In that case you go to her/him for help. If you have the authority to do it yourself, you do it in the settings of your organization. Click the symbol for your organization and Administer participants, chose Students. In the list of students you click the name of a specific student and then you choose to remove her/him if that is what you wish to do. Click Delete Account.