Thanks to MSET9, developed by Zoogie, it's now possible to install the Luma 3DS Custom Firmware on all Nintendo 3DS consoles with the current firmware. This method does not only support original Nintendo 3DS and Nintendo 3DS XL/LL consoles, but also Nintendo 2DS, New Nintendo 3DS, New Nintendo 3DS XL/LL and New Nintendo 2DS XL/LL. The custom firmware can for example be used to play homebrew apps and mods like CTGP-7.
Currently, MSET9 supports firmware version from 11.4.0 to 11.17.0-50E.

Timestamps:
0:00 Intro
1:51 Python installation
2:36 MSET9 setup
5:16 3DS part 1
6:53 MSET9 part 2
7:45 3DS part 2
9:47 Cleaning and possible errors

Links:
Python: https://www.python.org/downloads/
MSET9: https://github.com/zoogie/MSET9/releases
Part 2: https://www.dailymotion.com/video/x7yjirv
Part 2 (YouTube): https://www.youtube.com/watch?v=Jh2eLEvvKQw
Discord: https://discord.gg/YZjaedq
My website: http://flashkarten.ml