Nintendo Support: How to Remove an SD Card or microSD Card
How to Fix the 'No Accessible Software Data' Error on 3DS
I'm using this new micro sd card in my 3ds, it's formatted to fat32 with 32kb clusters and is detected normally in my pc, but I get a could not detect microsd
How To Transfer Data From Your Old 3DS To Your New 3DS - Game Informer
Nintendo Support: How to Insert an SD Card or microSD Card
REPLACING OR UPGRADING THE 3DS SD CARD WITHOUT LOSING ANYTHING - Sthetix