While it’s been a year, LG hasn't yet released the Android Nougat update for LG G4, which is more capable of running the operating system due to the fragmented nature of Android. We're sure that LG is working on the update; however, not everyone has to wait for the official update.
If you want to update your device manually, you can do this by installing CyanogenMod 14.1 custom ROM. Not only will this ROM supercharge your device and give it new features, but it will also be updated to the latest version of Android. Follow these steps to install this ROM on your device.
What You Need
• A rooted LG G4 with a custom recovery installed
• ROM File H811. Download here.
• ROM File H815. Download here.
• Gapps ZIP. Download here.
• Ensure that your phone is currently running h811 - V20O / h815 - V20D stock ROM or higher.
Step 1: Firstly, download the ROM file and the Gapps ZIP to a folder on your computer. Connect your device, copying both files to their internal storage.
Step 2: To install the ROM, you have to reboot into Recovery. Power off your device, and then press and hold Power + Volume Down until your device boots into Recovery.
Step 3: In Recovery, make a backup of your current ROM, and then navigate to Wipe. Perform the Wipe Data/Factory Reset operation.
Step 4: Navigate to Install, and then flash the ROM file after the Gapps ZIP file.
And that's it. Reboot your phone to enjoy the new ROM.