I didnt feel like doing a new thread for this. So I will explain here how to unroot or go back to stock mode.
First make sure you have LGNPTS installed (Go here
and follow the guide until the step where you need to select the .bin file)
Open LGNPST and make sure that you are under Provision > Upgrade. Then choose the .prl and the .scr files from the guide to their destination just as the above guide says it.
Then download this FILE
, extract it and select it as the .bin file.
Click START you will need your spc code just look in the guide above to get it.
Let the process gets to 100% and your phone will be back to stock mode.
Hope this helps guys