I know it isn't funny now but later .. I did the same thing not long ago. What a crapass sinking feeling!
Fortunately I knew where all buttons should be and with rumble on(it vibrates when you hover over a button) I changed it back. Even though nothing showed on screen I knew it was there because of the rumble.
Funny now but then I thought well it is my 2nd Wii so imagine. I will try to get the steps for you.
Oh nevermind I just read your edit lol.