So I am part of that program. If you go through the AT&T website to do your upgrade, select the option to upgrade your phone, the website will prompt you to pay the remainder you owe (if you do) for the amount to upgrade your phone. I was on the 24 month program and I had 2 months left to go so I had to pay off 2 months and the website charged my credit card for those 2 months I had left. Then when you select the new phone during the checkout process it will say how you want to pay for the new phone, you can either do Next 30 (get an upgrade every 2 years), Next 24 (get an upgrade every year), or pay it outright. After selecting the payment plan you are finished the checkout process.