In order to root your device, first you have unlocked the bootloader of the device, then you have to flash the recovery image via ADB &Fastboot command and then you can flash the SuperSu root file using TWRP recovery to Root LGv20 .Don’t worry we will be sharing step by step guide to Install TWRP recovery and Root LG V20 (Unlock bootloader and root lgv20 ) We are highly Thankful of me2151 senior member of XDA to sharing the root and unlocking bootloader process.  (Unlock bootloader and root lgv20 )

WARNING:

This replaces your current bootloader with a debug bootloader. If you plan to lock this bootloader you’ll brick your device. AS OF without delay there’s NO way to REVERT TO STOCK! FLASH AT YOUR OWN RISK! rootmygalaxy.net will not be held responsible for any kind of damage occurred to your LGV20  while following this tutorial.Do it at your own risk.  

PRE-REQUIREMENTS:

Make sure battery percentage is more than 60% Make sure you have installed LGV20 Drivers on your PC Install ADB&Fastboot drivers on your computer.Guide  Quickest Way To Install Android ADB and Fastboot (with drivers) on Windows or How to Install ADB and Fastboot on Mac or Linux Now Enable Developer option.Guide  How to Enable Developer Options & USB Debugging on Android

DOWNLOADS

TWRP Recovery for LGv20 Supersu to Root LGv20 LS997-deODEXd-signed.zip for Sprint users only.( to fix issues ) v20-root.zip Terminal Emulator

How to Unlock bootloader and root lgv20 (LS997-VS995-H910-F800L)

First of all Download all the required files from above Copy all the files of ‘Required Files’ ( Inside the V20-root.zip ) in your ADB and Fastboot directory. Copy and paste twrp-3.0.2-1-us996.img in your ADB and Fasboot installed directory. Connect your LGv20 to your computer and check if ADB is working If you are on windows then double click on RUNMEFIRST.BAT then a window will open ( Don’t close that window ) after it again double click on Step1.bat If you on MacOS/Linux  Enter this code (#=Comment) ./RUNMEFIRST.sh # OR bash ./RUNMEFIRST.sh Open the another terminal in MacOs/Linux and type this code ./Step1.sh # OR bash ./Step1.sh When you run the sh or bat file then you will see error on two files  Flatland and Flatland64. this is normal don’t get panic. Now wait for shell prompt and then type this code run-as con chmod 0777 /storage/emulated/0/* On Android open the terminal emulator and type this code ID Then you will see untrusted_app command is displayed ( this mean everything is going correct) Now type the following command in terminal emulator. applypatch /system/bin/atd /storage/emulated/0/dirtysanta See the RUNMEFIRST Dialog which tell you to run step2 In windows Double Click on Step2.bat on MacOs/linux issue the following code. ./Step2.sh # OR Bash ./Step2.sh Done !  you are in bootloader now.

HOW TO INSTALL TWRP RECOVERY AND ROOT LGV20 (LS997-VS995-H910-F800L)

On Windows run Step3.bat  On windows/Linux ./Step3.sh # OR Bash ./Step3.sh Now you are in main lock screen issue the following command adb reboot recovery Now on TWRP swipe to allow system modification. Now Flash Supersu according to your mobile model. For Verizon (VS995) and ATT(H910) Tap on install and flash Supersu Then go back to main screen tap on Wipe > Format all data > Yes Again go back to Wipe > Advanced > Tick dalvik , data and cache  > swipe to wipe, Go back and reboot your phone For Sprint(LS997) On main screen tap on wipe > Advanced > Check Dalvik, System, Data and Cache > swipe to wipe Again go back to wipe > Format Data > Yes Go back and tap on install and flash  LS997-deODEXd-signed.zip then Flash SuperSU.zip Go back and reboot your device. DONE !!

You have successfully Unlock bootloader and root lgv20 Source: XDA  

How to unlock bootloader and root LG v20  LS997 VS995 H910 F800L  - 82