First of all, you have to update to Evolve+ 2.6.0
You have to update the de_DE.po from sources so that it grabs any missing strings.
After translating you need to compile and update de_DE.mo file.
I am sorry, but you have to learn how to use poedit
I had updated the strings and use google translate for German translation help, so the word may not be correct.
Please download the following zip file. Unzip and you will find the updated de_DE.po and de_DE.mo
I am able to do the translation.
Please see screenshot.
If you are still having translation problem, you can open up contact.php to physically edit the text or hire a developer from http://jobs.wordpress.net/ to assist you in doing the translations.
That’s all I can help for this issue.