Good afternoon, Brittany,
If the forms are specific for the students and they took the test as the wrong student, you will manually have to enter the student's responses. We do not have a way to move scans from Student A to Student B.
The quickest way to correct this would be to enter their responses under the Scan window - check the box in front of the student's name > Edit and the edit window will pop up for you to go down through and edit the student's answers.
Please let me know if you have any trouble with this.