JinKazaragi: It works fine, you should remove the english audio files before you copy over the jap. ones though otherwise the characters start to speak english at the additionally voiced parts because those weren't voiced in the jap. console verison (and becasue of that there are no jap. audio files for that lines of course).
chiper25: which file i should delete?
All of them and than copy the japanese audio files into the folder, There are way to many to make a list of them or to bother figuring out which ones exactly.
Or just wait for the official patch which was announced,