Just update via system settings.
1. EmuNAND is a much safer approach to homebrew than messing with your system NAND. If something happened to your EmuNAND, the worst that happens is you have to either set it up all over again using the virgin SysNAND you have, or if you were smart and made a NAND backup of your EmuNAND, restoring that. It's much easier to replace SD cards than it is fixing a NAND chip when it's near dead from all the flashing and such.
2. I appreciate the fact you just asked instead of being hugely persistent and hell bent on this person to install custom firmware another way. The thing is I don't think people in this thread need a reminder of what's out there, they are well aware, but they wanted to use something different to achieve essentially the same goal as the modern setups. The way I see it, nobody really has a right to say anything on the matter given they didn't pay for the systems being used for this, it's the responsibility of the respective individuals whether people like it or not.
Message to anyone reading this:
If you can offer help to what these people use, then help, if you don't know anything on the matter, it's just best to leave the topic alone, and worry about your own stuff.