Someone PM'd me asking more details so I figured I'd post it here.
1) Click link in registration email to change registration.
2) Use your confirmation code to log in.
3) Press cancel.
4) There should be a button to make appointments. Goes where I drew the red box. I don't see it now. It looks like the system is down again.
http://i.imgur.com/Q9CpNAr.jpg
5) Pick a day to schedule the appointment.
6) The top line is your schedule. It should be white if you have not scheduled anything. Click the button in the column to the left of the schedule to search for companies. You put the name of the company in the "NAME" box, NOT the "COMPANY" box. Not intuitive I know, but it's how it works. There will be five or so choices under that name. These are the recruiters. You can only search one recruiter's schedule at a time. try to find a mutual time that works when the recruiter has a WHITE box. The recruiter's schedules are the line below yours. I don't know why some have two lines, sorry. Red is busy, pink is an appointment that's been made by someone else but not confirmed by the company so only make appointments in the white boxes. To choose the time, do the drop down menu below the schedule. Click next and make sure it is the correct time.
If you can't find a time that works with one recruiter, go back and search for the company again and choose another recruiter.
Within a couple days all your appointments should be confirmed. I'd double check to make sure you were not accidentally double booked with someone else and yours was canceled. I'm not sure, but I don't think there is anything preventing a double booking.
Good luck.