Search the web for a guide, Using DVD2Xbox on your Xbox transfer the game from the DVD Drive to the HD. Then using FlashFXP Transfer the Game onto your PC. Then Using Craxion 4 Convert and patch the files to an ISO. Then Burn to a DVD using DVD Decrypter or another ISO burning prog.
download clonedvd2 and anydvd. clonedvd2 is to burn xbox games and anydvd takes off the protection on games so u can burn them
also if you're running avalaunch you can just use quix. It qill ftp the game off your hdd and convert it to an ISO ready for burning all in one fast easy step. For the burning of almost ANY image I recomend ALCOHOL 120%.