Yeah but I guess replacing the center channel of Adywan's edit with the one from the german DVD won't work,
because there are new sound effects and new music on the center channel of Adywan's edit that are missing on the original DVD.
You have to contact Adywan for his sound effect track and music track.
Nevertheless there are several ways to extract the center channel. One way is to use BeSweet. This program is able to split the 5.1 audio of the DVD into 6 single mono wave files. One of them is the center channel.