PC drives will not read Xbox discs. There are drivers and firmware that make it possible but those are buggy and shite. To rip it to your computer you need to have FTP access to your xbox, pretty much a modded system with a dashboard.
You will then have to put the game in your xbox and make sure autolaunch is turned off in your dashboard. The way to get the files now is to access it through FTP and read the D:\ drive on the xbox as it is the DVD-rom. Now FTP all files from the disc to a folder on your pc. Alter the files you want and then use craxtion or Qwix to create a XISO. Now burn that Xiso with whatever program you want.
The easiest way to mod PES on the xbox is to have a large Hard Drive that you install the games to. This way, you only have to FTP the patches over to the xbox where the game is located. If I did nothing but confuse you here, try
http://forums.xbox-scene.com/