I remember how I flashed my Nintendo DS. In the back of the device there's a sticker over a screwhole. You'll need to poke a screwdriver in there, but inside i

I remember how I flashed my Nintendo DS. In the back of the device there's a sticker over a screwhole. You'll need to poke a screwdriver in there, but inside is not a screw. It's an electrical contact to make the ROM read-write which your screwdriver needs to bridge, and stay bridged while the firmware is flashing (It is harmless if the contact is loss in the process, but I don't know if it would be safe to abort at that point) Pretty hard to convince someone to do that process, yet doable by anyone with a flathead screwdriver. I guess nowadays it become Samsung's e-fuse where if you flash it blow an e-fuse and the status of the fuse is now detectable with software. Then apps can refuse to service people just because the custom firmware fuse was blown.