The method from the other thread works fine. Just convert your save to PC save and use Hyne.
I already tried to do it, but when loading the game it tells me that the file is wrong and it doesn't load, what can I do?
If you are following the guide, it's missing a key step. After you press ctrl+b and paste/write the modified save back into the original save. You need to update the first two bytes with the new save size.