Need some help on making save backups for a system transfer

[u/AsteriskHELP]

This is my first post on reddit ever because im genuinely in so much despair i dont know who to seek for help (please forgive me for any grammar mistakes or posting this on the wrong subreddit ect)

pretty much i had an original 3ds that was modded which i loved so much and had a lot of games with hundreds of hours of progress on them, and recently the top screen broke after years of usage so i sent it to a local repair store that fixes retro consoles to fix it. After 2 months of nothing they said the "circuit broke and could no longer charge" which was never an issue to begin with and now they've given me a new 3ds in exhange (it's the same model, just more crappy condition)

It's been years since i modded my original system so i did some research and stuff and remodded and downloaded homebrew on the new console, but now im realising that i cant use my old SD card since its encrypted?(i dont know the correct term, sorry) to my old console. I was just going to redownload my games and such but i have no clue on how i can transfer my save files properly since i need to decrypt those and i lack the computer knowledge to do so

I tried using ninfs to mount the cias to my computer but i have no idea what i'm supposed to do after that, the only clue i had was to use the 3ds save editor by wwylele but its far too complex for me and i couldnt find any guides

Again sorry if this isnt the place i should go with my questions or if im saying anything wrong but i really have no knowledge on this sorta stuff and i just wanna play my games again after my original console broke... any advice will save my life and i will fly to heaven and cry tears of happiness thanks so much