It's too easy - you can get it from the WoG download. Or you can look for links in the [Release] Questpaket 4 thread. Attention: you should delete superfluous characters (marked by red color) from the end of links to the first part of archive: %22.
QP v4 Update 2 has a complete translation from German to English, Italian and Spanish languages. Update for QP adds compatibility with CP v1.75 and translations to Polish and Russian languages.