How difficult to mod my Xbox?

I've been thinking about it or awhile, but is it easy like a software install, or massive soldering and modification on the hardware side. I am looking at making one into an all-inclusive retro gaming machine. Maybe there is an online tutorial that someone could point me to?

This : http://forums.xbox-scene.com/index.php has been the gospel for me since '03

I know little about soft mods but I always did a full mod
There a few, very few mod chips still around, and if your console is a later version (1.6) that takes a little more work as well

There is a member on there that did chip install for me for $50 (25 for chip/25 install), I had him do it as I no longer have a programmer, and its crazy cheap

I can send you a link for the Auto Installer software, it's real easy and sets up your new dashboard, has all of the apps and emulators

I now have 3 original xboxes modded all running XBMC and full emulator packages and love it