Woot, i got it

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Very simple, in a bunch of steps:
0. Get the latest version of Dolphin SVN, and compile it, (versions 657 and up).
1. Make a copy of your old MemoryCardA.raw (the one that has the savegame you want to update), save it with whatever name u want, i'll name it Copy of MemoryCardA.raw
2. Delete MemoryCardA.raw.
3. Start the game you want to recover your savegame from with the new Dolphin.
4. Save the game whenever possible, and close Dolphin.
5. Now get your favorite hex editor (HxD for me), and compare both files.
6. You want to replace the directory entries from Copy of MemoryCardA.raw with the ones from MemoryCardA.raw, and nothing else (read YAGC, to understand what you need to do).
7. So search for the name of the game (Smash for Smash Brothers Melee for example, and replace the ones in the old memcard (Copy of MemoryCardA.raw), with the ones in the new memcard (MemoryCardA.raw). It's not easy to explain, but once u understand what you are doing it's very easy. Basically you need to add some additional info, to the directory entries, the game's "code" for example, like GALE01 for Smash Brothers Melee.
8. Once u've done this, delete MemoryCardA.raw, and rename Copy of MemoryCardA.raw to MemoryCardA.raw.
9. Now open MemoryCardA.raw with Dolphin's memcard manager to update the checksums.
10. Enjoy your updated savegame

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get your favorite Hex editor, then