Download and install:
Copy PG86IMG.zip file to root folder on SDCard, copy Virtuous_Shooter_v.3.0.0.zip file to anywhere in SDCard. Shutdown your phone.
Press and hold Power + Vol Down to boot into Bootloder. See image bellow.
Device will auto detect firmware file and confirm "Do you want do start update?". Press volume buttons to choose "Yes" answer and wait a moment. Once done, you will see that screen. Remove SDCard.
Press Power to reboot your phone. When phone is starting, press and hold Power + Vol down again to go Bootloader mode. Choose "Recovery" option.
See images bellow for detail:
+ Do wipe data/factory reset.
+ Do wipe cache partition. Go Back
+ Choose "install zip from SD card".
+ Choose "choose zip in sdcard" and select ROM Virtuous_Shooter_v.3.0.0 file. Once done, reboot your phone again.