Here is the guide to setting methods for the Global Support compatible model you have rented or purchased.
Turn on the power of the au mobile phone, and then take out the "au IC card."
Turn off the au World Service compatible model you have rented or purchased and insert the "au IC card" as explained in the instruction manual.
au World Service compatible model rental
When you turn on the power overseas, make sure to switch the settings to overseas mode before using. The telephone will automatically search for a signal appropriate for use.