I couldn't find a subforum for Elex, so I'll just post here...
I forgot the change the language to German when downloading Elex, but didn't notice it at the time.
After installing Elex I noticed that the game was in English, I checked the options but could not find any setting to change language to German, I also searched for config files and even in the registry, but did not find anything.
When I take a look into the game files though, I can see files for every language. like c_0_de.pak c_0_en.pak c_0_pl.pak so the language must be installed... the question is, how do I switch between them? (at least I assume those are language files because it very much looks like it)
The problem I have is that I cannot re-download the entire game in German because I have limited internet traffic. So in case those are not language files, is it possible to download like a language pack?
Thanks in advance.

Not sure if this is the case but it MIGHT be that the installers in general are identical and only the way the files are installed is changing depending on the installer used. So it might still be that all you need to do is to change a setting in a config file or some registry keys. I would love to help you more or give you more detailed informations but unfortunately I haven't even finished downloading yet. I can take a closer look when I have finished downloading but I cannot guarantee that I will do it today because it's getting late and I have work tomorrow. I will however try to help yuu more as soon as I can.

Edit:
I found the solution to your problem. Just like I thought the installers are identical but the configs used are different. Open the file ConfigDefault.xml in folder "\ELEX\data\ini" with an editor like notepad ++. Serch for language and change the two values (should be in line 247) VoiceLanguage and SubtitleLanguage from "English" to "German". I had no problems turning my German version from German to ENglish this way so it should also work the other way around :)

Devs should really add this option in game.

I just tried your solution, and it worked for me! Thanks a bunch, I really didn`t wanna play it in english, since I am from Austria and always played the Pyranha Bytes games in German.

Glad I could help. :)

Thx a lot. It works also with Czech lang. :))

Thanks! This just saved me from downloading it a third time. ( Because after I had downloaded 6 parts first time, they switched from 1.0.28xx to 1.029xx just when I clicked on part 7 and I was like... no way now :/ )