deschris
MXIII always had S802 soc.
Yours may be a MXIII Plus if it has S812.
I have a MXIII 1GB and a MXIII 2GB but not a MXIII Plus.
If yours is a MXIII Plus, then
the starting point would be Drieschel's S8X2 build
Unzip it to empty microsd and use the toothpick method
The endpoint for you would be LibreELEC-S8X2.arm-8.0.1-M8S.tar (I think)
Edit: I thought wrong, correction as per Demetris - LibreELEC-S8X2.arm-8.0.1-MXIII-PLUS.tar
The remote.conf file is in your /etc folder in Android. You need a root explorer to access that file on your kitkat install. This needs to be copied to the ConfigFiles smb share or /storage/.config folder if doing over sftp/scp or using pendrive