Use this tutorial at your own risk!
This tutorial is only for devices with 6820 & 8810 cpu
If you will like to flash devices with new cpu and use many more functions with this tool, buy their box and get an updated version of the software.
>Download an install spreadtrum drivers here for manual installation click here
>Download and extract gpg dragon from here
>Launch GPG Dragon
>Click on Spreadtrum Tab
>Under Mobile Option, Select 6280_Android or 8810_Android
>Click the button with 3 dots [...] near C:\Temp_File.bin bar
>Select the pac or bin file you want to flash
>Click Start Button
>You will see Scanning USB Port
>Connect the spreadtrum device you want to flash to PC while holding volume down button
>GPG Dragon will Read the phone info and the pac or bin file info then you will see a message Waiting for your confirmation...
>Tick the partitions you want to flash and select OK (do not untick anything if you want to do full flash)
>You will see a purple progress bar with percentage completed.
>When flashing is complete, you will see a message All Done!
>You can now disconnect the device and reboot.
For those who want to remove pattern lock or Google account but too scared to do a full flash, just tick only UserData and flash
or still you can follow the tutorial here