Simply copy the m23base.php file from your preferredly understood language to the directory of your translation. e.g. if you want to translate the english version to german: copy /m23/inc/i18n/en/m23base.php to /m23/inc/i18n/de/m23base.php.
Now translate the text between the ' " 's.
e.g.
$I18N_help="Help";
becomes
$I18N_help="Hilfe";
Please don't delete any other text and make changes only between the ' " ' letters. Don't translate something like $I18N_help to $I18N_hilfe. If you do so, m23 can't find it and will leave the place, the text should be appear empty. For your information: m23 stores the texts as variables that are inserted at the right places in the m23admin interface.
root
2018-05-08