Two screws are hidden underneath two rubber feet highlighted in red.
Use the tip of a spudger to pry the rubber feet out of the lower case.
Depending on the age of your device, the rubber feet may crumble apart as you pry them out. If so, use a fine-tipped tool to scrape out any stuck pieces of rubber.
Carefully lift the lower casing from its bottom edge.
The lower case is still attached to the motherboard by the volume and SD board cable highlighted in red. Do not try to completely remove the lower case of the DSi yet.
Pry the volume and SD board cable up from its socket on the motherboard using a spudger.
Once the cable is completely removed, then you may take off the entire outer casing.
Use your fingernail or the edge of a plastic opening tool to flip up the retaining flap on the following three ZIF sockets:
Lower touchscreen cable
Lower LCD cable
Power board cable
Be sure you are prying up on the hinged retaining flaps, not the sockets themselves.
After flipping up the locking tabs on all three sockets, use your fingers or a pair of tweezers to gently pull the cables straight out of their sockets.
Desolder the speakers from the upper LCD by heating up the solder joints with a soldering iron and simultaneously using a pair of tweezers to pull the speaker wires away from the logic board.
If you have never soldered before, we have a guide that makes it easy.
The tricky part is getting the upper screen and black ribbon through the hinge. I found that curling them and pushing them through a drinking straw that was cut short first and then pushing the straw through the hinge hole made it a whole lot easier.
So true. I just broke my second ribbon cable while replacing the case. While most repairs on the dsi are relatively easy, this ribbon cable makes any repairs that involve it a nightmare.
I curled the larger (new) cable the same way the smaller one was already curled. Just spend some time doing that until it was shaped that way and it was a lot easier to get both through the molded tube and ring.