How to Install CM13/Android 6.0.1 Marshmallow ROM on Galaxy S2! [RePartition]
Marshmallow ROMs require minimum of 1GB of system partition while the Galaxy S2 defaults to 500MB. To do this, it’s pretty simple to do, you just need to install repartitioning zip file using latest TWRP recovery.
First, make sure you have a custom recovery such as CWM or TWRP recovery.
Second, boot into your current CWM or TWRP recovery and flash the ISO Rec TWRP recovery. Then reboot into recovery.
Third, flash the repartitioning zip file. Make sure you have backed up everything on your phone beforehand as there is a chance you may lose some of your data during repartitioning! Once that’s done, reboot back into recovery.