How to move iTunes Music Library from an external HD to another?

Question

Yesterday I tried to move all my music from an external HD to a new bigger one.
Well, I encountered various problems, the most important one is that the “iTunes Music Library” file messed up.
I transferred all files and both “iTunes Music Library.xml” and the “iTunes Library” file in the new HD. I have to say that I didn't know so much about those two files and I thought that it was enough to move them in the new location; I discovered that those files included the information about where the music is located (among other infos), so it still redirects to the older HD.
However, now I’m trying to recreate the previous situation on the older HD, and I’m trying to “rebuild” the iTunes Library (I have a back-up of the xml file, even if it is not the running one).
This operation is very important for me because about two years ago I used (for a long time )an earlier version of iTunes that had a bug: even if wrote all the tag infos on an a mp3, the “artist name” and “album name” tags didn’t remained. But I still can see all the informations through the iTunes browser (thanks to the iTunes Music Library DB). So, I cannot recreate it from zero. I absolutely need to export the existing “iTunes Music Library” to the new HD, or at least to use the existing “iTunes Music Library”, leaving it where it already is and moving only the “iTunes Music folder” (even if I don’t want to use two external HDs, the older one holding the existing “iTunes Music Library” e “iTunes Library” files and the newer one holding the “itunes Music” folder I moved!).
As far as you know how can I move safely “iTunes Music Library” e “iTunes Library” files on the new HD applying them to the new “iTunes Music” folder??
I really need your help!
This article http://docs.info.apple.com/article.html?artnum=307074 didn’t help.
Stefano

Answer 1

Sorry, I wasn't responding to you, just the original poster. I didn't look at the date on that posting and didn't realize that you'd added a post that wasn't quite the same problem. In future, you'll find you get better answers if you start your own thread. You're issue really is a bit more complicated.
If iTunes currently recognizes all the music on both internal and the external drives, it should work. You have to make sure that both drives (old and new) are mounted. Make sure you have both "Keep iTunes music organized" (you probably already do) and "Copy files to iTunes..." (you probably don't) checked.
If not all of the music is currently in your iTunes library, perform the procedure with the music that is a part of the library and add the other stuff afterwards.
Best of luck.