Step 2. Download atmosphere sigpatches from here (these enable you to run game dumps, and use homebrew NSP applications like Tinfoil. If the links opens like a folder, click the download arrow near the top right.)
Step 3. Extract the contents of
atmosphere-X.X.X-master-XXXXXXXX+hbmenu-X.X.X.zip to the root of your SD card.
Step 4. Open the
fusee.zip and extract the
atmosphere folder in the archive to the root of your SD card (these are the patches that enable atmosphere to load game dumps and homebrew NSPs.)
Step 5. Put your SD card back in your Nintendo Switch.
Step 6. Inject fusee-primary.bin to boot your switch with a payload injector.
Verify you're running Atmosphere by looking in
System and you should see
Current Version: X.X.X|AMS X.X.X|X if you see this, congratulations, you're running Atmosphere.