At the main menu go to Extras, then to Codes to type in the passwords:
GM2OPEN8 All Gamemodes
A11T3AM5 All Teams
MAXSKILL Max. Skills
Z26BEXW8 Micro Soccer
E06J3CT5 New Object in Inventory
SPEEDY01 Unlimited Turbo
5Y104D9A Unlock Streetballerteam
WIMP_A.1 Weak Opponents