Log into O-Space
Select current course under gray heading "My Courses"
Select "Submissions" tab
Select the student's underlined name
Go through the list of Submission Assignments
Select "Step: 1 Title" under the assignment in bold
Scroll down page to middle for the "Evidence Added" box
In "Evidence Added" box will see in bold students submission with a red "Delete" next to it
Select "Delete" in red
Scroll down to bottom of page
Select "Save and Unsubmit"
You know it works because the next screen you will see a blue box under step 1