Tutorial:
1. Go into Player Match and click Playercard
2. Go to Leaderboards, Search and Destroy, then press "Y"
3. While still on the Change Filter screen, go to your party/friends list and join your friend who is in a Combat Training lobby.
4. Once you join you should see the lobby in the background, but still have the Change Filter screen up
5. Go back to your party/friends list and click on your friend and hit View COD Playercard
6. It should come up on your screen and you should be able to to press "B" until you are at the Edit Playercard screen.
7. Enjoy using your Combat Training points to buy and edit things on your playercard!