You will need three specific files moved to your phone's internal storage or SD card: Search XDA Developers for " Android 5.1.1 ROM" (e.g., CyanogenMod 12.1).
In the Android enthusiast community, firmware versions are occasionally shortened to major numbers (e.g., 511 = version 5.1.1, 442 = 4.4.2). However, for the GT-I9100, (the S II never received an official Lollipop update). The “511” tag in this specific case is likely a mislabelling from old download repositories where filenames or folders contained “511” as a random identifier, or confusion with later custom ROMs (e.g., CyanogenMod 12.1 – Android 5.1.1). Do not expect Android 5.1.1 features if you download a “511” labeled stock ROM for the GT-I9100 – it will be Jelly Bean 4.1.2. gti9100 firmware 511 download upd
Tap Reboot System . The first boot to Android 5.1.1 will take . Do not touch the phone. You will see the CyanogenMod or custom boot animation. You will need three specific files moved to
