Download and Flash Latest Unofficial LineageOS 14.1 Final Version Android Nougat 7.1.2 ROM For Samsung Galaxy S2 I9100 Device. this ROM is a free, community built, aftermarket firmware distribution of Android 7.x (Nougat), which is designed to increase performance and reliability over stock Android for your phone.
LineageOS is based on the Android Open Source Project including extra contributions from many people inside the Android community. It can be used without every need to have any Google application installed. Linked below is a package that has got from another project that restores the Google Apps. LineageOS does still include various hardware-specific code, which is also casually being open-sourced anyway you can also Download AICP 12.1 Android 7.1.2 ROM for Samsung S2 I9100
How to Update Samsung S2 to Android 7.1.2 LineageOS ROM
Backup your device data first.
Download lineage-14.1-XXXXXXXX-UNOFFICIAL-xxxxx.zip to your sdcard
Download Google Apps (optional)
Reboot device into download mode
Flash Resize pit in Odin. (only for i9100, i9100p)
Reboot into custom recovery mode
Perform A Full Wipe all your data
Flash LineageOS ROM from sdcard
Flash GApps from sdcard (optional)
Reboot to system and enjoy.
Check Also: ViperOS Nougat 7.1.2 ROM for Galaxy S2 I9100
Known Issues and Bugs
Everything is Working Fine.
Supported Devices and Variants
SHW-M250K (u1ktt) (Request Stock JellyBean Rom.)
SHW-M250S (u1skt) (Request Stock JellyBean Rom.)
Merge source codes from LineageOS.