I have dumped the NAND, and extracted the savefiles using HacDiskMount and the
extract nand gamesave.rar from
this thread. I checked the PLGP save file in PKHeX and works fine, but, after edit it, I don't know how to inject it again in my NAND.
When I used HacDiskMont, the saves were archives with just numbers, no extension, but after I extracted the savefiles from those archives with
extract nand gamesave.rar, I had one folder for each archive, and a savedata.bin, which is the one I used on PKHeX. But I don't think I can put that bin file again in the NAND just like that, it must be another archive without extension, like the original, but I don't know how to repack the bin into that archive.