How To Install Android 4.3 Jelly Bean (XXUGND2) On Samsung Galaxy S3

A new Android 4.3 Jelly Bean update is rolling out to Galaxy S3 owners in Russia, with other countries to follow. For users unable to get the new Jelly Bean update OTA, the following guide will walk you through the installation process.
Before Getting Started
Before you get started, ensure that your Galaxy S3 is the GT-I9300 model.
As always, you want to backup your device and charge it to at least 80 percent.
Finally, enable USB Debugging mode by navigating to Settings -> Developer Options.
Updating Samsung Galaxy S3 to Official Android 4.3 Jelly Bean (XXUGND2)
1) Download and extract the official Android 4.3 firmware, which can be found here.
2) Download and extract Odin, which is available here.
3) Boot your Galaxy S3 into Download mode by pressing the Volume Down, Home and Power buttons together until a warning prompt appears. Once you see the prompt, press Power to enter Download Mode.
4) Right click on Odin and launch the application as an administrator.
5) Using Odin, install the following files from the .zip archive downloaded earlier:
    A) Click AP button and select the .tar.md5 file.
    B) Click CP/Phone and navigate to the file with Modem in the file path.
    C) Click CSC and select the file with CSC in the file path.
    D) Click PIT and select the file with .pit in the file path.
6) Navigate to the Option submenu in Odin and check Auto Reboot and F.Reset Time. Uncheck Re-Partition.
7) Click Start and the installation will begin.
8) When the firmware has finished flashing to your Galaxy S3, your phone will automatically reboot.
9) Once your Galaxy S3 restarts, you will officially be running Android 4.3 Jelly Bean XXUGND2. Kudos.