I recently modified my XBox with a Xecuter 2.6CE chip, this is a quick run through of how I did it. All the information you need is out there I am simply trying to collect it together.
Please be aware, if you open your xbox you invalidate the warranty! I am in no way responsible for any damage you cause to your xbox. You will need to be competant at soldering, and a confident computer user to even think about attempting this.
These instructions will only work for an xbox 1.6 and an Xecuter 2.6CE chip, if you attempt this with a different combination you may well cause damage to you xbox.
To find out what version of the xbox you have check out the version detector
For a mod chip visit a supplier such as mrmodchips
If you have any further questions or queries I suggest you start on the forums of xbox scene
1 - Mounting the Chip
The first step in modifying (modding) the xbox is to physically open the box and solder the chip in.
2 - Installing a Bios
Once the mod chip is installed and the Xbox is back in one piece the next step is to install a bios.
3 - Xbox Dashboard
The Xbox has a sort of operating system called the dashboard, the dashboard runs when there is no game in the drive. You will need a new dashboard to run programs from your Xbox.