If you have the appropriate privileges you can unassign students from your class by following the steps below.
Click your name and then click Class.
Click the row with the student's name you want to unassign.
Click the X at the beginning of the row.
Click unassign to unassign the student from your class.
The student account will be removed from your class. The account will not be deleted and will still be avilable and viewable to the School and District Administrators.