Make sure your TV chassis is TPM17L, you can see it on the sticker on the back cover.
Enter this link and download this file:
https://app.box.com/s/bwibg3z0hqi62e5chuyk31qbpfyei5mo
Unzip the zip and you will get an "AUTORUN.UPG" file weighing about 35 Kb. You copy it to the root directory of a USB stick that is empty and formatted in FATxx, you click on the TV on and if there is no other problem you should start to update automatically.