When you start paying it, and agree to the terms, it then gives you options of paying the entire thing, or doing the payment plan. The payment plan info is on the website: http://seasonseats.torontofc.ca/payment-options.php
So you pay 20% up front (anytime before November 6th). And then 20% on December 10, 20% on February 4th, 20% on March 3, and 20% on April 7.