Norton 360 Multi-Device - renew subscription questions

At present I have Norton 360 Multi-Device. I would like to know the renew process with the following software.

As Norton 360 Multi-Device  was changed to Norton Security with Backup

Norton Security with Backup - should I uninstall and install the software or can I key the code for renew on the screen.

Windows 7 Home Premium x64 SP1, IE 11, Norton 360 Premier Edition 21.7.0.11

please advice how to renew my subscription.

thank you

rao