Very Important to do your Nand backup before you do CFW. More info at Making Nand backup with Hekate tool
emuMMC / emunand notice:
This tutorial will work for someone with emuMMC/emunand set up as partition on sd card.
This tutorial is also for someone who do not want to setup emuMMC/emunand or do not care about online play and ban.
if you want to setup emunand/emummc for first time, you need to go to the guide at switchgui.de
If you are switching from sxos to atmosphere, There is custom boot.dat to boot atmosphere for people who have sxos pro dongle at https://github.com/ELY3M/sx-custom-boot.dat-maker/releases
If you want to run clean/fresh Atmosphere
follow these steps
1. Backup your Nintendo and emuMMC (if you have this folder) folder on your sd card to your pc.
2. Format your sd card as fat32 with guiformat app. - if you get error. you need to kill explorer.exe with taskmgr then format then restart explorer.exe
3. download the latest Atmosphere zip file and extract to the root of your sd card https://github.com/Atmosphere-NX/Atmosphere/releases
4. download fusee-primary.bin, this is the payload you will use to boot your Switch. (It will go in your tegrarcumgui, on your dongle, on your phone)
5. download Sigpatches from here and extract to the root of your sd card.
6. copy your Nintendo and emuMMC (if you have this folder) folder back to your sd card and put your sd card back in your Switch.
7. get your switch in RCM mode then inject fusee-primary.bin
8. Hold R while tapping the Album Icon to enter the Homebrew Menu.
make sure to read my atmosphere tips here