Yes, you can. Caution:Removing an assignment will remove any scoring the reviewer has done on that applicant.
Step 1: Go to the assignment screen. To remove an assignment or multiple assignments first filter the list by Task Name, Committee and Reviewer. Click on Display Applicants.
Step 2: Place a check-mark in the student you wish to remove or use the Select: All|None feature.
Step 3: Once you have selected your applicants Click on the Remove Assignment Button