Just FYI (sorry for the bump btw), I just used the NDS Backup Tool to backup my M3 Real. It made a rom called "PASSCARD3_AMFE00.nds". It dumped very fast, and it made a file of 256 kB.I don't get where it's telling you to "Please rename PASSCARD3_AMFE00.nds of the backup to SoftReset.g6ds and copy it." Where do I find that stuff? It's confusing me!
It looks to me like you're supposed to dump the G6/M3 Real with his backup tool, then rename the resulting .nds file to "SoftReset.g6ds" or "SoftReset.M3DS". I don't have a Real (or an SCDS1) so I can't test it myself.
I renamed it to "SoftReset.m3ds". I fired up the 3in1 Expansion Pack tool and... It worked