hi, i got the solution via another forum. there are 2 options:
1. the elegant, but quite complex one (haven’t tried it yet): copy the language-files in the language folder of your theme (those en_EN.mo and .po ones). the path is wp-content -> themes -> your theme -> laanguages. download poEdit and translate all of them. then rename them, e.g. de_DE.po instead of en_EN.po and upload them. then alter following code in your wp-config.php to the language you’ve chosen, e.g.:
define('WPLANG', 'de_DE');
2. go to the functions.php of your theme via dashboard->design->editor. there you’ll find the section for the comment-form and all connected phrases. search for “leave a reply” and all the other phrases you want to change and translate them. also a bit difficult, but it works. disadvantage is that all the changes get lost once you update your theme:(.
hope that helps! cheerz…