EmuNAND can be updated the same way just as sysNAND.
But to retain the online credibility of your system you must update your emuNAND by offline means in order to avoid bans.
You can do so by getting your desired update firmware files (look for them online don't ask about them here). once they're done downloading extract the folder inside the zip archive at the root of the SD card.
Next, get ChoiDujourNX from here:
https://gbatemp.net/threads/choiduj...ller-homebrew-for-the-nintendo-switch.513416/
This is the app that you'll need to update the firmware.
Launch the app and navigate to your firmware folder and tap select,
You'll be displayed by a popup menu telling whether you want the exFAT patch to be installed or not, select it if you se exFAT SD cards.
Note: autoRCM should be kept on if you intend to preserve the number of fuses and prevent them from burning in case you want to downgrade later on.
On a last note, make. NAND backup in Hekate before proceeding with the update, just in case something goes haywire.