Please note that you can both delete and unlink a student:
Unlink - The student account will still exist and be accessible to the student, but it will not be associated with your teacher account.
Delete - The student account will be removed entirely, it will not be available to the student.
If you are using Google Classroom, please follow this guide instead: https://teachmehelp.zendesk.com/hc/en-us/articles/360055531253-How-can-I-delete-individual-students-
To unlink or delete a student:
1. Navigate to the classes tab
2. Click the edit icon next to the student you wish to edit
3. Click delete to completely remove the student account, or unlink to remove your association with this account.