Right-click only on part01.rar and select "Extract Here." The software will automatically pull data from the other parts to create the final .bin or .pkg file. Step-by-Step: How to Flash the Firmware
While forum links are common, always try to contact Nordmende support or authorized service centers first to ensure you have the latest, virus-free version.
If done correctly, an "Upgrading" bar should appear. Do not turn off the TV during this process. Safety First!