Edit | Edit student name
This option allows you to edit what is normally fixed and unalterable - the column of student names. Selection of this option un-fixes the names column, and puts the grid into editing mode.
This means that not only can you edit the names, but you can in fact change any cell in the grid. Click on the cell you wish to change, then type in the new value, using the Delete and Backspace keys as appropriate.
Remember to Save after editing. In this case, Saving will return the grid to its normal state of fixed names column, and editing not allowed.