Ok I made some progress (yeah i know, sounds stupid, but i start from far)
I root the devices, added the Apps2SD package, isntall a terminal box apk; and tried to launch the script fix_permissions.sh with the link above
I ran this in super user;
#sh fix_permissions.sh
: not found
: not found
: not found
: not found
fix_permissions.sh : 77: Syntax error : word unexpected
Any clue what i need to do next ?