Did this today, it took about four and a half hours. By far the most difficult thing is curling those cables through the hinge hole. That took a good hour to figure out. Read the comments that are with that step, it’ll help. There is no way I would have figured this all out without this guide - thank you! The 3DS powered up and worked great! (Well, after I took it back apart to slot the volume slider to hit the switch correctly. And then took it apart one more time to fix the buttons that had become displaced while I was fixing the volume switch). :)
This is the crazy hard part of the process. Be patient and it should eventually work. I found that reassembling but leaving all of the pieces out of the case (screen, camera harness, speaker harness) helped. It’s nearly impossible to do this if the screen is sitting in it’s normal position - the corner of the screen blocks a part of the hole. Assemble it all outside of the case, curl up the harnesses, and then work them through the hole. Once you have that done, then snake the wifi antenna through the hole. And finally place the screen into place (and the speakers/cameras/led). This probably took me an hour to figure out.
Oh, and once all of that was done *then* I worried about curling things up again and getting that black bushing over the cables. I doubt I could have done it with the bushing in place in the hole.
When reassembling you may find it difficult to get the bar back into the hole in the hinge. A couple of tips:
* Reassemble it with the clamshell pieces in a ‘closed’ position (same position that you took it apart).
* The pin/bar may have rotated slightly during disassembly (mine did). It only goes into the hole one way - the hole is actually a slot. If the alignment is off even a couple of degrees it won’t pop back in. If this happens simply lift the edge with the bar up out of the hinge and push the bar so it pops back out (like it was going into the hinge). The take a pair of pliers and gently rotate the bar to fix the alignment, pop the bar back to the ‘unhinged/open’ position, then reassemble.