Disclaimer; I'm not responsible if any thing goes wrong, and your 3DS bricks.
This is a simple tutorial I am making if any one needs it, this is more for developers than the average users as it is a Dev FW. I only tested this on my 2DS so far so if you have success please say so in the comments. The firmware CIAs are USA region, so if your 3DS is not USA, use Plailect's guide to region change to USA.
Update; There seems a problem installing Dev FW on N3DS, I do not know a way...
[Tutorial] Installing Dev Firmware and Dev Apps on Retail 3DS
This is a simple tutorial I am making if any one needs it, this is more for developers than the average users as it is a Dev FW. I only tested this on my 2DS so far so if you have success please say so in the comments. The firmware CIAs are USA region, so if your 3DS is not USA, use Plailect's guide to region change to USA.
Update; There seems a problem installing Dev FW on N3DS, I do not know a way...
[Tutorial] Installing Dev Firmware and Dev Apps on Retail 3DS