Step 1: in folder "Buoc 1"
- Flash 14.1.B.1.532 by flashtool. Start phone, turn on USB debugging (skip lost imei and signal then continue)
Step 2: in folder "Buoc 2"
- Copy 3 file in folder "Buoc 2" to phone.
- Reboot phone into Team Win. ( Press Power wait green led then press and hold "volume -" until red led release "volume -"
- Wipe -> advance wipe -> tick dalvik cache, cache, data -> wipe
- Install 3 file Rom, Recovery, SuperSU -> Do not reboot but go back to the main menu, then go to reboot->power off
Step 3: in folder "Buoc 3"
- Copy file in folder "Buoc 3" into fimware of flashtool
- Run fashtool flash file C6802_14.3.A.0.757_TW kernelonly.ftf.
- Reboot phone
Another way better
You do Step 1 then reboot TWR flash c6802_14.3.A.0.757__flashable.zip --> power off phone --> flashtool flash C6802_14.3.A.0.757_Stripped.ftf --> finish