Upgrade or Install Samsung Galaxy S6 SM-G920I to Android Lollipop 5.1.1. The firmware available for downloading http://www.sammobile.com/firmwares/database/SM-G920I. You can download your Samsung Galaxy S6 SM-G920I firmware at the page, available for some countries. How to Root for Samsung Galaxy S6 SM-G920I is the separated post, this post only for upgrading to Android Lollipop.