Xbox discs can only be ripped via your Xbox because a normal optical drive cannot read the discs. So, in order to do this you have to set-up an FTP connection with your Xbox and before you can do this, your Xbox has to be modded. Once your Xbox is modded and you can FTP to it and from it then insert your Xbox game and make sure it doesn't boot automatically (modded Xbox'es have an option for this). Once the game is loaded fire up an FTP client on the computer your Xbox is connected to and connect to your Xbox. Then browse to the DVD-ROM letter of your Xbox and transfer the files from the Xbox to your own computer. Now you can burn these files with software like RecordNow Max and play these back-ups on your Xbox. This brief explanation will most likely raise a lot of questions if you've never done this before but you can find a lot of tutorials online that can help you with it. But, they all require that your Xbox is modded so it will accept back-up copies and an FTP connection. Good luck!