Upgrade or Install Samsung Galaxy A3 SM-A300G to Android Lollipop 5.0.2. The firmware available for downloading http://www.sammobile.com/firmwares/database/SM-A300G. You can download your Samsung Galaxy A3 SM-A300G firmware at the page, available for some countries. How to Root for Samsung Galaxy A3 SM-SM-A300G is the separated post, this post only for upgrading to Android Lollipop.