Open Dolphin and load a Wii game that uses Mii data
Go to the Wii system menu inside Dolphin
Open the Mii Channel
Create or select the Mii you want
Use Dolphin’s NAND files to access the saved Mii data
Locate the Mii save data in the Dolphin user folder
Check the Wii save data folders for Mii-related files
Copy the Mii file from Dolphin’s NAND directory
Rename or export the file as needed to use it elsewhere
Use a Mii editor or converter if the file is not already in .MII format