I'm assuming its already flashed and installed, adn you have evox, so all you have to do is use flashfxp to ftp into your xbox and then transfer the d folder over to your pc and then back to a folder on your hdd.
When my brother modded his xbox he put in a 120GB hard drive and installed a program called xCommander. xCommander lets you copy and delete files to and from the xbox hard drive without using your computer. Takes about 15 minutes per game. ~Twinkerules