Nice guide, but it came too late for me.
I already did irrepairable damage to my DS while trying to swap cases last month. Specifically, I broke the microphone wire right at the connector head making it impossible to solder back together and I somehow managed to totally unseat on of the shoulder button microswitches from the PCB. so I'd advise anyone taking their DS apart to be especially careful of those two points. Especially the should button microswitches. The mic wire was pretty much my fault, but I really have no idea how the shoulder button became separated and from looking at it now, it seems like it was already a weak point in the PCB design.
This was doubly disappointing to me since the clear case that I was installing ended up having a wobbly hinge once it was all together and, honestly, not looking all that hot anyway. In fact, after about 10 minutes, I decided it wasn't worth it and decided to switch back to my original white case, which was actually when I made the two mistakes described above.
For the most part, the disassembly wasn't as difficult as I thought it would be, but I can only recommend being very careful, especially around the shoulder buttons. And if you're doing this in order to install a replacement case, maybe think again.
...word is bondage...