PhD qualifying exams MUST take place within a two week window, and the Oral Examination must take place within two weeks of completing the last qualifying exam. Given this, and the fact that you need to coordinate the schedules of several professors for the Oral Examination, you need to schedule backwards, as it were:
Step 1. Schedule your Oral Examination date and time with your entire committee. When you are doing this, you probably should take a look at the Exam Coordinator Calendar to make sure there are sufficient openings for the qualifying exams in the 2-3 weeks prior, but DON'T complete Step 3 until you have completed Steps 1 and 2.
Step 2. Contact the Events Coordinator to book the room for your Oral Examination.
Step 3. Schedule the qualifying exam dates and times with the Exam Coordinator via the Exam Coordinator Calendar.
Step 4. Complete the Qualifying Exam Application Form, including all required signatures or email approvals. Be sure to scan and email a copy to the CST Exam Coordinator and to submit a scanned copy or hardcopy to the Registrar's Office.
Step 5. Study. A lot. :-)
Step 6. Arrive 10 minutes before the exam, take a deep breath, then kick its proverbial butt! :-)