It's possible, but it can be difficult. EDIT: If you need pictures, go here. This is an article for the retail, but all the steps are the same as the ones i wrote, except for number four, and number six. 1) Remove the faceplate. 2) Break the seal if it hasn't been done before, and unclip the plastic clips in the front. 3) Remove the bottom grey piece, by looking for the grey plastic locks through the holes. Find these, and use a small object to press them down, while trying to pull the piece off. Do this four times, for each clip, and it should just pop off, just like the retail 360. 4) The top (sidecar) is different. You use the same process as with the bottom, except when you finish unlocking the clips, the sidecar won't come off all he way. You have to pull it out enough so that you can remove the casing. 5) Now the tricky part...You need to be VERY careful with this, or you can break the case. Make sure that the clips that are right under the faceplate are unclipped. Then go to the back of the xbox. There should be about 10 small holes at the crack, where the two pieces come together. You can either make an object to push in these holes to unclip the clips that are holding it together, or you can do like what I had to do once, and use a box cutter, if you do this, be very carful, because you could get cut, an if you slip, it could scratch the xbox, and that wouldn't be good at all. While using what ever to press against the clips, pull up on the case as if you were trying to pull it apart, when you unclip one clip, it will make a pop noise, when you hear this, just go to the next hole and do the same thing, when finished pull the case apart, but be very careful, because the sidecar barely comes out of the holes at the top. 6) Now that you have the bottom part of the case off, use a torx 10 (i think) screwdriver to remove the Long silver screws from the case, if I remember correctly, there are five, maybe six. Now that you have the screws out, flip over the xbox, and pull the top piece of the case off. Now you can see the innards of the xbox. At the top where the sidecar is, there should be a hole where wires are going to the motherboard from the sidecar. Unplug the wires, and carefully pull the sidecar away from the xbox. 7) Now you should have the sidecar removed from the xbox.
FYI once the side car is removed you will need the wires for the dvd drive to main board. Also on removing the white case there are special tools that you can buy to make it easier. You also may want to check out Llamas they have a number of articles on taking apart a 360.
