The Samsung Galaxy S3 is a pretty old device that has been axed from any further updates by its manufacturer. Regardless of that, there are still many S3 users around and they are able to stay relevant through updating via unofficial means.
The latest update available for the Galaxy S3 is the Android 5.0 Lollipop. Thanks to the XDA Developers, S3 users can now experience the latest Android OS from Google. If you are an S3 user and wish to install the Android 5.0 Lollipop on you device, we have the instructions right here for you.
Pre-requisites
Make sure your Samsung Galaxy S3 has the bootloader unlocked, is rooted, and has a custom recovery like PhilZ Touch recovery installed. Also, you must have a minimum of 50% battery before commencing the installation.
Flashing Instruction
• Download the arter97 kernel file and arter97’s Android 5.0 Lollipop update firmware.
• Extract the Lollipop ROM ZIP file and put the ROM back-up in the following location – /sdcard/clockwordmod/backup on your Samsung Galaxy S3. Also transfer the kernel zip file to your SD card.
• Enter recovery mode on your device and perform a full wipe of the system, cache, dalvik cache, and data.
• Restore back-up. This will actually install the Android Lollipop ROM to your device, as you have stored the 5.0 firmware in the backup folder on your device.
Once the installation is complete, the S3 should perform a long restart. Upon completion, the smartphone will run on the latest Android 5.0 Lollipop.