Except for the chat applet Zammad does not use any translation files.
I really do not know which file from where you did find - I also can’t find any fitting files within our zammad/zammad repository.
Translations are stored within the database. No, please don’t fiddle in it directly.
Instead, use the translation endpoint within the admin menu of Zammad.
You can find more information on this page regarding this topic:
https://admin-docs.zammad.org/en/latest/system/translations.html
You can also push your translations to the central translation server of Zammad to help other Zammad users.
If this is not the translation you’re talking about, please let me know which “homepage” you’re talking about and which file (from where) you exactly mean.