CyanogenMod team has released nightly builds of CM 11 ROM for non-Nexus devices including Samsung Galaxy S3 (I9300). This ROM brings the latest Android 4.4 to Galaxy S3 (to international version). As an official Android 4.4 update for Galaxy S3 will take quite a long time to arrive, installing the CM 11 ROM lets you enjoy Android 4.4 Kitkat right on your Galaxy S3.
The below guide lets you know how to flash official CyanogenMod 11 ROM on your international version of Samsung Galaxy S3 (I9300) as well as installing Gapps (Google apps) on it. However, keep in mind that it is a nightly build, so it contains bugs.
Disclaimer: Please follow this guide at your own risk. We can’t take responsibility for anything that goes wrong. This guide is intended for technically talented users only.
1. Samsung Galaxy S3 should be rooted and a custom recovery installed.
2. Make a Nandroid Backup from custom recovery
3. Backup all apps, contacts, SMS and other phone data to Sd card or PC
1. Download the latest CM 11 ROM zip file and the Gapps zip file and and transfer both to your Galaxy S’s SD card.
2. Turn off your device and boot into recovery mode, then perform “wipe cache partition” and then “wipe data/factory reset”.
3. Now, from recovery select “install zip from SD card”, then “select zip from SD card” and then choose the CM 11 ROM zip file.
4. Again select “Install Zip”, then “Select Zip” and choose the Gapps zip file.
6. Finally reboot your device.
You have now successfully installed CM 11 ROM on your Samsung Galaxy S3 (I9300). If your phone stuck at booting (boot loop), perform “wipe cache partition” and then “wipe data/factory reset” from recovery and then reboot your device.
Note: The ROM is still in preliminary stage and does contain many bugs