Battery Life: Charge your device to at least 70% to prevent shutdown during the flash.
Use titanium backup or similar tools, as this will wipe the phone.
Without restarting the phone, repeat the process: choose the and confirm installation. 5. System Reboot
In recovery, perform a "Factory Reset" or "Clean to Install a New ROM." Wipe Cache Wipe Dalvik Cache 4. Flash the 5.1.1 Firmware