Use a tool like WinRAR or 7-Zip to extract part1.rar . It will automatically pull data from the other parts to create the final folder.
Ensure your device's motherboard ID matches "s706C-7731-D2" exactly. Flashing the wrong version can permanently damage (hard brick) your hardware. Download File s706C-7731-D2(168)-V1.0.part1.rar
Flashing firmware will erase all data on the device. Back up any important information if possible. Use a tool like WinRAR or 7-Zip to extract part1