Instructions
Start the game and load your saved game file.
Go to the DigiColiseum and talk to the monster behind the counter. After some conversation, a menu with options will appear.
Select "Digi-Matching" by highlighting the option with the D-pad. Press "A" to select it.
Move the D-pad to select one of your Digimon, and then press "A."
Choose the Digimon from your friend's list that you want to breed with your selected Digimon. Press the "A" button and a Digi-Egg will be created.