At the player creation screen, hold R2 + L1 + L2 and press Triangle, Circle, Square.
Go to the 80's Legend team and hold L1 + L2 + R1 + R2, then press Square(3), Circle(4), Triangle, X(2), and Select. Go to exhibition mode and press L2 for "Rewards". The reward "Legends" will now be available. Enable it, exit exhibition mode, and then enter the "Rosters" screen. Take Kareem Abdul-Jabbar off free agents and put him on a team. Start a game in exhibition mode. Kareem Abdul-Jabbar should be on the team you placed him on.
Michael Jordan is not in the game at all but you can create a player and name him Michael Jordan. The announcers will say his name.
To get Iverson's arm band, select all arm bands in create a player mode. It will look like Iverson's arm band/sleeve.
More Salary Cap Room
Go to "Roster Management" and release a team's highest paid player. Then start a franchise and you can sign the player back to the team for the league minimum.
Increase Super Star Stats
Press Circle at the main menu to access the active menu. Choose "Roster" and then "Edit Player". A Super Star player will appear if your "Create A Player" list has no entries. Press R2 to increase the players stats. Press L2 to return to the "Create A Player" list, then press Start to change to another player.