How to install Android 4.1.2 Jelly Bean Avatar ROM on Galaxy S2 I9100

Samsung Galaxy S2 has recently received CyanogenMod 10.1 update based on Android 4.1.2 firmware. CyanogenMod ROMs are for being high-customizable on top of being light and feature-packed. Another group of developers are into making things a lot better than they already are; the group built the Avatar ROM that offers even more ways to customize