Refer to the readme.txt inside the downloaded zip if provided.
Since the TH-32ES480DX is widely sold in India, the primary source is: Panasonic Th-32es480dx Software Update Download
If your TV cannot connect to the internet, you can download the firmware file from the Panasonic Global Support site. Download Information of TV | TV | Digital AV | Support Refer to the readme
: Press the [HOME] or [MENU] button on your remote control. Panasonic Th-32es480dx Software Update Download