Step.1Download drivers and install
Step.2download offline flasher from Here
Step.3+ Turn off the phone, press the 3 key (Power + Volume Up + Volume Down) to select the mode on the screen. Use the Volume Down key to scroll to "PLD DOWNLOAD" and then press the Power button to select it. Your phone will switch to S / W Upgrading. Now, connect your phone to the computer using MicroUSB cable.
Step.4 You do Offline Update tool has been run previously by
others in his or v1.2 or less, please FixServer.exe file before running okay!
+ Running Run_Sky_Server.exe window will appear blue,
do not miss this one off during flash offline!
+ windows update web interface of the sky will appear.
+ Click Upgrade button S / W and wait results offline!
In the worst case the driver can not be installed automatically and Button S / W does not appear, then please re-install this
driver: 
+ After flash is complete blue back window click on it and press any key to litter cleanup program for your self after flash. Any comments please Write Here
Step.5this step is to execute the process. now you have download the rom and download.inf file.
Unrar the offline flasher and put it anywhere in the computer. put the inf file in the sky home directory inside the offline flasher and copy the downloaded rom that has .BINX extension into the main directory inside the sky offline rom flasher. connect the phone which is in S/W upgrade mode and connect to the pc. and goto the offline flasher and run Run_Sky_Server file, you will see a blue little screen appears along with the internet explorer. now dont worry for the language, just press the main blue button as shown in the image
and you are all set to upgrade the firmware.