Things You'll Need
Instructions
Turn on your Wii, select the "Mii Channel," and then select "Start."
Point to one of your Miis, then hold down the A and B buttons simultaneously and drag and drop the Mii into the circle on the left called "Edit Mii."
Select the leftmost tab at the top of the Mii editing menu and then select the field under "Mingle." It will say "Off" if the Mii is not mingling yet. Select "Mingle" when prompted. The field will be changed to "On."
Select "Quit," then choose "Save and Quit."
Repeat steps 2-4 for each Mii that you want to Mingle.