To renew, go to the "Extensions" menu item and select the subscription you wish to purchase. When you renew, you basically go through the process as if it's new, but you'll see a discounted price at the checkout page if your subscription is still active.
It's been a long time coming but the new site rollout should be happening later this month, with incremental improvements every week until the final design is fully turned on.
Sorry for the confusion, and hope the above helps,
Alex
Not clear what to click on to renew
