contact on Twitter: "#Nintendo #switch Just updated my FW to 9.0 1 thanks to #hekate (backup) & #ChoiDuJourNX (upgrade). trick : modify "BCT.ini" in #atmosphere (0.10.1) folder with "nogc = 0" if
How To Upgrade/Downgrade Switch Firmware Offline! - YouTube
ChoiDujourNX - Offline Switch Updates and exFAT Driver Install (No Burned Fuses) - CFWaifu