WiiFlow can extract Wii gamesaves to a emu nand and flash them back to Wii nand but sometimes you need a bit more. That's where SaveGame Manager GX comes in. SaveGame Manager GX lets you extract, compress, install, copy, move, and delete Mii's and gamesaves for Wii, WiiWare, and Virtual Console games. Download it here - https://static.wiidatabase.de/SaveGame-Manager-GX-Beta.zip
Unfortuantely SaveGame Manager GX can be a little tricky to figure out at first. Here are some quick tips to help the beginner.
First thing to do is go into settings and set the custom paths.
Choose the item you want to set the path for. A new window opens for you to choose the device and folder.
click on the device icon to select the storage device to use.
browse the folders available and choose one.
if you need to rename or make a new folder click on the folder in the upper left corner.
when you made your choice click on the check-mark or else click the X to cancel.
Second, if you want to mess with saves on an emu nand go to features menu in settings and set emu nand browser to ON.
Now you should be ready.
When you select a gamesave you are given some choices of what to do with it. The choices vary depending on if it's the Wii, an emu nand, a official compressed data.bin, or a folder backup. Here are the choices and what they do.
Extract - copies a save to a folder with the name 00010000 + the 8 digit hex number of the ID4 of the game. This is savegame manager format.
Compress - copies a save to a folder and compresses it just like the Wii does when you copy a save to SD. You end up with a data.bin file.
Install - copies the save to the Wii or an emu nand. Works with compressed data.bin files and savegame manager format files.
Copy, Move, Delete - these three are obvious.
Decompress - decrompresses a compressed save into savegame manager gx format.
Here are some scenarios:
(wii = system nand)
wii to emu nand - wii mode, select game and choose install
emu nand to wii - emu nand mode, select game and choose install
emu nand to another emu nand - emu nand mode, select game and choose extract. Now go to settings and change emu nand path. Then go to folder mode and find the save and select install and choose the new emu nand.
You can also choose to edit all the saves instead of individual ones by clicking on the little circle with arrows down by the big config icon.
Note: when working with the Wii SD card private folder don't forget it might also contain channel data too. Those will be content.bin files.
Note: To install a save you are required to have a savegame already on your Wii. Just run the game once and make a quick save.