I think it maybe possible for you who are new in gadget world. We can talk more about Root first. If you don’t know, root is an administrator that can allow you to install or uninstall the application that usually can’t do by common user and you can modify the operating system. You will need root further for application like market enabler, titanium backup, ROM Manager, and more also modify themes, boot animation, battery indicator, and more.
Ok, now, lets start to apply how to root, and in this occasion we try it on LG Optimus 3D
-          Before to root, you need to download
  1. SuperOneClick and extract
  2. Driver LGUnitedMobileDriver_S4981MAN32AP22_ML_WHQL_Ver_3. 2.1.exe
-          After that, get the installation of
  1. Install Driver LGUnitedMobileDriver_S4981MAN32AP22_ML_WHQL_Ver_3. 2.1.exe on PC
  2. I suggested to restart your PC
Now, you can begin to root, please follow the step below with your own risk, you get this step carefully
  1. Open your phone, enter Settings > Applications > Development
  2. Disarray USB Debugging
  3. Get connected between PC and your Optimus 3D phone through data cable
  4. Look over notifications in your phone, if it can be detected “USB debugging connected”
  5. See “device manager” on PC, is the driver has installed as well
  6. If the driver has installed, please open up superoneclick app (if used windows vista/7, run on as admin)

7. After the app open up, you go more with choose ‘psneuter’ in exploit
8. Choose Root

9. The process will look like in this below
10. Wait until the process done like in image