I have a hard time overwriting labels that the FOS user bundle for Symfony2 uses.
I\'m already overwriting the Form class, but there is no option for elements like \"set
You don't need to overwrite Form classes.
Copy/paste vendor/friendsofsymfony/user-bundle/FOS/UserBundle/Resources/translations/FOSUserBundle.xx.yml
files in your app/Resources/translations
directory (with the same directory structure and the same file name) and redefine translations to your convenience.
edit: As told by @mario-johnathan, overriding translations is not part of bundle inheritance. See http://symfony.com/doc/current/cookbook/bundles/override.html#translations for official documentation