When your players have possession of the ball, do the following. Go to Team Management and press "Substitution", click on the player that has the ball, and swap him with another player that is already on the field, so that they swap positions. Return to the game and the player will magically transform into the player that he swapped positions with. This will be more noticeable if the players are of different races.
Use the "Player Edit" option to change a player name to one of the following entries. The corresponding selection will be unlocked on the "Special Options" box that appears:
CHEAT FUNCTION - CHEAT CODE Big head mode - eac rocks or gabo Take A Dive - johnny atomic or cartman Crazy ball - dohdohdoh or mrhat Invisible walls - ur1ofus Hot potato mode - xplay or gonzo Silly moves - footy or powder Classic 1982 match - zico Classic 1966, 1970, 1974, 1982 matches - hurst Crowd leaves stadium - city Ball on fire - kenny Skeleton players - kyle Alien mode - neila