Obtain a Chao from Sonic Adventure. You will be
asked for the next area when your Chao reaches
the end of the current level. Select the desired
location, then immediately press Mode.
Then, press Mode(2) to return to the Chao
Adventure screen. Allow the Chao to start
walking and it will allow you to select the next
area. This may be repeated as needed.
When battling two of your own chao, its not
fatal. Choose battle and the game will load the
two Chao onto the VMUs. Then, disconnect so you
will only fight a clone of your Chaos.