Renew my subscription

My subscription is up for renewal in few days. I bought the software Norton Security Premium - 1year (electronic download)

The box says also include Antivirus, etc I thought Norton already does antivirus, why special mention of it on the box?

How do I Renew it as the box has no cd. Please let me know the steps to renew my subscription.

PS: Win 7 Home Premium, Norton Security with backup version 22.9.4.8

Thank You

Rao