If you cannot find the specific split archive parts online, the most reliable way to update your firmware is through the TV's built-in system settings or by contacting the manufacturer directly. :
: Do not turn off the TV or remove the USB until the process is 100% complete, as this can permanently damage the software. Where to Find Firmware Files Download ONIDA LEO40FAIN Software part5 rar
Hold the on the TV (not the remote) for 5–10 seconds until the LED starts blinking, which indicates the update has started. If you cannot find the specific split archive
Finding the specific "part5.rar" file for an Onida LEO40FAIN Download ONIDA LEO40FAIN Software part5 rar
Copy the firmware file to the of the USB drive (not inside any folders).