The Moto G2 (XT1068) shipped with Android 4.4.4 (KitKat). But they were OTA upgraded to Android 5.0.2 (Lollipop) or Android 6.0 (Marshmallow), depending on the region. If your XT1068 is one of the newer Androids and you wish to downgrade back to the original KitKat that can be done easily.
You will loose all the data and apps on your phone. Back up whatever you need.
Download the KitKat image of XT1068 from here.
Download the MFastBoot tool from here.
Connect the XT1068 using a USB cable to the computer.
Unzip both of the above files into the same directory. Open a command prompt at this directory.
Run the following commands to replace its OS with KitKat:
mfastboot.exe flash partition gpt.bin mfastboot.exe flash motoboot motoboot.img mfastboot.exe flash logo logo.bin mfastboot.exe flash boot boot.img mfastboot.exe flash recovery recovery.img mfastboot.exe flash system system.img_sparsechunk.0 mfastboot.exe flash system system.img_sparsechunk.1 mfastboot.exe flash system system.img_sparsechunk.2 mfastboot.exe flash system system.img_sparsechunk.3 mfastboot.exe flash modem NON-HLOS.bin mfastboot.exe erase modemst1 mfastboot.exe erase modemst2 mfastboot.exe flash fsg fsg.mbn mfastboot.exe erase cache mfastboot.exe erase userdata
That is it! You must have your KitKat back now 😊