This is done in the final volume of the "Agent Silent Death" Freedom Chronicle DLC. You have to kill General Dunkel as he is leaving the moon base, and there's a few Supersoldaten among other things that spawn on your way out to him.
You should of course be playing it on one of the harder ones such as Mein Leben.
YouTuber "Kreeper V" 's guide on Mein Leben, like always lol, is the best resource for these DLCs. Volume 3 in the video begins at "9:46" and lasts till around the end of the video. Volume 3 on the moon base is probably the hardest section of the game regardless of the difficulty you are playing it on... I find it to be pretty challenging at least.