In Pro Evolution Soccer 6, you could add new faces using DKZ Studio which is a great editor for customizing the entire section of the game, from colors, to stadiums, images, faces, etc.
You can import faces using the application mentioned. You will need two .bin files which are a player's face and their hair. Open the application, and locate 0_text.afs file and navigate to the player's name. Use the import function and select the BIN files and replace them with the player you want. Build the database again and play the game. The players will have new faces and hair.
