Main menu, press on the envelope, on new message / create message (my screen is in Japanese so not sure what it's called with you), address list, then entry / record or something then you can choose between WII or others. Choose WII and then you can enter the WII code by pressing on the text "enter WII code". The rest will follow automatically.
This profile is no longer in use, see my other profile *~Onna76~*