Hi mate. I can write you a quick (and very easy) tutorial for editing the music files in PES6 if you mean the PS2 version?
OVERVIEW:
Create ADX files from MP3 files
Insert new ADX files into O_SOUND.AFS
You will need the following programs:
Nero Wave Editor
DkZStudio (the latest version is the best, but it is in spanish.....)
1. Get hold of an O_SOUND.AFS map from somewhere so you can decide what tunes you want to replace. I have one if you need it.
2. Use DkZStudio to extract the O_SOUND.AFS from your PES6 ISO and put it into a folder you can call PES6 AFS
3 Open the O_SOUND.AFS yuo just extracted using DkZStudio. Select the file you want to replace and right-click on it. Choose 'Open using - Audio Player. You will hear the tune being played so you can be sure its the right tune.
5. Make a note of the number of the file to be replaced. Close DkZStudio.
6. Open Nero Wave Editor. Open your MP3 track and then go to Edit - Convert Sample Format and then set the sample rate to 24000, the bit depth to 16 bit (CD & DAT) and keep the anti-aliasing filter as Fast. Press OK.
7. Choose File - Save As (chose .WAV file type) and call the file the same name as the file in your O_SOUND you want to replace.
8. Do this for all the tunes and save the .WAV tunes in a folder called WAV Music.
9. Open DkZStudio again and choose Tools - ADX <> WAV Tool. Select your WAV Music folder with all your .WAV files you made using Nero Wave Editor in the first box. In the next box you should choose the destination folder for the newly created ADX files. I recommend using a folder in the DkZStudio (I always use the TEMP folder in C:\Program\DkZ Studio.
10. Start the process and wait till it's done.
11. Open your O_SOUND and insert the new ADX files over the old ones. If the new file is larger it will tell you so and you will need to rebuild your ISO, if the song is smaller you won't need to rebuild.
Any questions, just ask!