Adding or removing students from a roster updates the roster for everyone that the roster is shared with.
Steps to Add or Remove Students from a Roster
Go to Setup,
Click the “Add or remove students” button, and you’ll see the same screen you used to create your roster.
To remove students
Select students and click “Remove”
To add students
Click "Add Students" in the top left
Select a roster to pick students from
Select the students and click “Add Students” in the lower right corner
Rename a roster on the Roster Picker.