If Mailchimp for WordPress is not yet translated in your language or you’re spotting issues with the current translation, you can help translate the plugin on WordPress.org.

After logging in with your WordPress.org account you can submit your translations right away, after which a moderator will approve them. Usually translations are approved within 2 weeks.

When a language is completed for more than 90%, users on that language will receive an update notification in their WP admin asking them to download the updated language files.