Idk if this was posted but I think I just got rid of the update nag (since it's not appearing anymore). Anyway, to get rid of the update nag once the notification pops up and asks you if you wanna update your 3DS hit Accept, now it'll tell you to agree to the terms of service, here you hit decline and voila no more nag. I just did this and this is the fifth time (I believe) I turned my 3DS on and no notification. I hope this is a permanent solution since it's not bothering me anymore be it that my 3DS has wifi on or off (Blame the android keyboard for any spelling mistakes). If someone else posted this feel free to delete this mods!