a) load the unzipped files to an empty flash disk ( make sure no other files in the same flash disk)

b) Connect the Flash disk to USB in put while the DVD is ON...DVD screen turn to blank and informed with upgrade prompt menu.
   press enter button on the RCU to start the software upgrade.

c) Soon the software upgrade is  finished, remove the USB flash disk from the USB input....and start to check the RCU functions.
 
Please NOTE :- DO NOT INTERRUPT THE DVD POWER WHILE UPGRADING IS IN PROGRESS.