To reschedule an appointment, 

1. Navigate to the top-right corner. On desktop you click on your name in the top-right corner. On mobile click the the Menu icon (three horizonal lines)
2. Click on the login button and it will ask you to enter the Username (as in your Email Address) and Password. This should be one which you had setup at the time of enrollment. If you have not enrolled, please do so.
3. Once logged in, you will see your name on the top right corner. Next to it will be a drop down arrow
4. Click on the drop down arrow and select Manage Appointments
5. Under Upcoming Appointments, you will see the option to reschedule your appointment