One way is to select the option of upgrading using the web server. The prerequisites for that will be as follows:
1. You need to have access to a web server on a network accessible to your appliance.
2. You need to have the IP address of the webserver.
3. You need to have access to the NetApp CLI (can be normal user with admin permissions to upgrade).
While upgrading you can use this command software update http://web_server_ip_address/path/<file name> -f