You'll need to complete the Examination Request Form a few weeks in advance. Get the form at this link: eecs.northwestern.edu/forms/eecs-exam-request

Also, be sure to check in with the EECS Graduate Student Affairs Office personnel in Tech L351 (phone: 847-467-2165) for specific requirements, and make sure your Advisor knows what your plans are.   Read the appropriate sections of the Graduate Study Manual for loads of pertinent information.