The folks at CyanogenMod have released a Marshmallow Android 6.0.1 ROM for the Samsung Galaxy S2. That is pretty damn amazing considering the smartphone was last seen in 2011.
I couldn’t resist giving it a try to see if it worked, but it does and it runs nicely surprisingly on only 1GB of RAM.
If you are going to give it a try out, chances are your SGS2 has Android Kitkat 4.x installed on it, which means the kernel and recovery will be too old. The partition for marshmallow is different as well so that will have to be formatted.
If you don’t have the patience to read through 1273 pages of forum to find out about the bugs and problems or how to do install it, then keep reading below… I will provide the instructions and links.