Step 1: Go to 'My Group' from the top menu.

Step 2: Click 'View' next to the group you want to edit.

Step 3: Click on the Add Students button.

In the pop-up window:

Step 4: Select the Grade of the students you want to add.

Step 5: To add all students from the selected grade, check the 'Select All Students' box.

Step 6: To add specific students, check the boxes next to their names.

Step 7: Once selected, click 'Save and View Group' to confirm the changes.