1. Download .kdz file for your v20 model from the following links. Currently v20 models available are:
F800K, F800L, F800S, H915, H918TN, H990, VS995, H990N and H990DS
2. Search, download and install LGUP ( LGUP_Store_Frame_Ver_1_14_3.msi ) and a file called LGUP_common.dll
2a. Copy the LGUP_common.dll to C:\Program Files (x86)\LG Electronics\LGUP\model\common (May need to modify folder access right)
3. Search, download and install LG Driver ( LGMobileDriver_WHQL_Ver_4.1.1.exe )
4. Completely Power off the v20 ( or to remove and put the battery back )
5. Plug the USB end of sync cable to your PC
6. Press and hold "Volume Up"
7. Plug in the USB-C end of sync cable to the v20. The phone will enter download mode (or Firmware Update). Now you can release the "Volume Up".
8. Run LGUP. The program will regconise the v20.
9. At the file path, click "..." and chose the .kdz file
11.Click "Start" and wait until the process is complete.
Now we have a safe method of restoring bricked v20. Hope developers can start trying to root without worrying of bricking the phone.
This method is verified on my H990DS. If anybody successfully flash using this method please let us know. Thanks!