If you need to make a Factory Reset on your LG WebOS panel, please follow this steps:
Step 1:
Press for a few seconds the Settings button in the Remote control until a white bubble appears in the top-right corner of the screen.

Step 2:
While the bubble are in screen, press 0, 0, 0, 0 and OK. You will see the Signage Settings Menu appears.

Step 3:
Inside Under Signage Setup, scroll down to the Factory Reset options.

How to factory reset your LG WebOs screen

Step 4:
Select Factory Reset, Confirm and OK.

How to factory reset your LG WebOs screen

After a few moments the screen will be reset.