Caution: Flashing custom firmware can brick your device and voids your warranty. Ensure you backup all data first. How to Install Android 6.0.1 Marshmallow On Galaxy S3 (4K)
Now that you have Marshmallow running, here is how to make the most of it: sm-g530h firmware 6.0 1
: A TouchWiz-based custom ROM that mimics the official Samsung interface of newer devices. Requirements for Installation Caution: Flashing custom firmware can brick your device