To remove a user from a group select “Manage > Users and groups” from the top menu and click on that learner in the list to access their profile page.
On the user’s profile page, in their details panel, click the bin icon next to the name of the relevant group.
The user will no longer be able to see the courses available to the group. However owners will still be able to view results from previous attempts.
NB Removing a user from a parent group will automatically remove them from the child groups beneath it. Learn more about group hierarchies.