How to upgrade the Galaxy S3 T999 to Android 4.1.1 Jelly Bean build UVDLH3

Samsung Galaxy S3 is an awesome smartphone that powered by Quad-core 1.4 GHz Cortex-A9 processor.It have a 1GB of RAM and is available with built-in 16/32/64 GB storage option. With 4.8-inches Super AMOLED capacitive touchscreen Galaxy S3 is a cool smartphone to have.

Compatibility

This ROM and the guide below are compatible only and only with T-Mobile Galaxy S3 T999 variant. It is not compatible with other Galaxy S3 variants or with any other device. 

How to update Galaxy S3 T999 to Jelly Bean UVDLI3 Android 4.1.1 OTA

Firstly Connect your Galaxy S3 to computer.Now copy downloaded zip file to SD card of your phone.After downloading process completes switch off smartphone then wait 5-6 seconds for vibration to confirm complete switch off.Put the Galaxy S3 T999 in Recovery Mode by pressing and holding Volume Up, Home and Powerbutton until Samsung Galaxy logo appears in phone screen. Wait few seconds and our phone will be in recovery mode. In recovery use Volume Keys to jump through options and Power button to select an option.Now, Select Apply update from External Storage and then locate and select the OTA zip file that you copied in Step 2. The OTA flash process then start.
Once OTA update is flashed perform “Wipe Data/Factory Restore” (Will format your internal SD Card).
Now go back to the main recovery menu and select reboot system now to reboot the smartphone. The first boot will take time, so be patient!Congrats! Your Galaxy S3, model number T999 should now run on Android 4.1.1 Jelly Bean build T999UVDLI3.