I'm going to add a comment to example_submission.txt and then save the file locally as example_submission_v2.txt. I'm then going to provide this slightly modified file back to the student by way of feedback on their work so far.

Click on the Grade link in the status column, along from the student's name. The feedback dialog is displayed:

2. In the bottom half of the Feedback dialog is an area allowing me to provide feedback (in the form of Response files) to the student. Also, listed are the files the student has uploaded (in this instance, just one). Recall that when I was logged in as a student, I pressed the Send for marking button. This was to confirm that I thought I had finished the assignment, and it also prevented me from uploading or modifying files. Because I don't think this particular student has actually finished I can press the Revert to draft button to allow the student to modify and submit files again. If it is displayed...