Check the Toshiba or JVC support pages for your specific model number.
Extract the files (usually upgrade_mb130.bin or similar) directly to the root of the USB. Unplug the TV from the wall. Insert the USB into the TV's USB port. on your remote control. While holding OK, plug the TV back into the power.
Since Vestel does not provide a public "one-click" database, users typically find links through community-driven archives: