If you look in the forums over at
www.xbox-scene.com you will find information on how to obtain needed files, very useful guides on how to install different exploits and so on.
If you have any of the following games original release (not "best of.."/"classical" version) and a xbox mem card you can easily install any of Krayzies installers and have EvoX and all that setuped at the spot.
Splinter Cell
007: Agent under Fire
Mech Assault
if you do not have them but can obtain them thats good, otherwise hotswapping or similar is the way to go... :-\
If it comes to that I am to no help here as I haven't done it and don't feel like doing it.