You can remove someone (learner, facilitator or coach) from a course within the Access tab of a class activation if they no longer require access.
Select Access.
Find the relevant person and check the tick-box in their row. You can select multiple people at once.
Select Actions.
Select Remove from the course.
Select Remove now to confirm you want to remove the people you've selected.
Those you've removed will now no longer have access to the class activation. You'll see a confirmation message on your dashboard.
If you need to add someone back onto the course, you can do this via Access.