Legion

I'm not that familiar with the audio file storage structure (in fact I didn't even know there were non-English voice versions of KOTOR on PC), but as a guess I would start by taking the entire audio file directory (which I think is most likely the 'streamwaves' folder, though possibly some in 'streamsounds' as well) from your PC installation and dumping it in the Override folder of your Android version. If that doesn't work, you might need to batch change filenames of your German language audio to be the same as the English language versions, so that the Override folder does properly override the original English language voice files saved in the OBB. In most games that would involve renaming the 'de' part of filename to 'en'. See how you get on.

Modding KOTOR on Android actually seems to be very straightforward, as proven in this thread: http://www.lucasforums.com/showthread.php?t=217762 You just dump your mod files in Sdcard0/Android/data/com.aspyr.swkotor/files/override - forget about mucking around with the obb files! So far I have just tried Weapons of the Old Republic and HK-47 Melee Saber Mod - both work perfectly on my Galaxy S5. Of course you don't have the command console on Android which may limit what you can do, however fortunately savegames from Windows will import directly across to Android (copy into dcard0/Android/data/com.aspyr.swkotor/files/saves). All this means I can resurrect my long-abandoned modded dark side playthrough of KOTOR (last played in 2011!) for playing on my phone. Hurrah!