Ok, guys, good news, I managed to:
- Modify and rebuild any CIA updates (But you need to use the clean update as a base, you can't create the update from nothing),
- Rebuild a custom .3ds with all extra files (manual, updates, dlplay, etc.). These extra can of course be edited, like a custom manual.
I still need to try to convert it directly to .cia without .3ds first, but I have no luck for know.
Anyways, you can always convert it to CIA using 3DS Simple CIA Converter (3DSSCIAC, shorter).
But in this case, 2 things:
- Updates partition 6 and 7 will be removed (due to 3DSSCIAC).
- You need to encrypt the custom/created .3ds with Decrypt9 (using NCCH/NCSD Encryptor), then generate the ncchinfo.bin using 3DSSCIAC, then generate xorpads with Decrypt9, then convert it to CIA like usually (using generated xorpads + the new encrypted .3ds (our custom .3ds)).
I will update the tutorial asap