You can add/remove participants in Classroom from the “Participants” tab:
1) Add participants
Let’s say you’re conducting a group class and you missed to select/invite a student when creating the classroom. In this case, you can simply add that student by clicking the “Add participants” button in the “Participants” tab:
After that, you have to select the students/groups you want to add as participants to the class:
You can also add multiple students/groups. Finally, click “OK”:
And you will see them being added as participants, and they will be able to join the class:
2) Remove participants
If you added a student to the class by mistake and you want to remove that student from the class, or if you want to remove a spammer in an open classroom, you can click the “X” mark across the participant to remove them:
Then click “Yes” to confirm removing the participant:
You will then see the participant has been removed from the classroom. They will no longer be able to join the classroom again unless you manually add them again.