1) Download and install FileLoader. If you already have it, skip this point.
2) Add folder FileLoader into .../KONAMI/Pro Evolution Soccer 2014. 
3) Add these lines to your map.txt in GDB:

player=4522,"C. Ronaldo"

4) Enjoy ;)

FAQ:
1) FACE IS NOT APPEARING IN GAME

Make sure that you add folder to right place. Also check if you have rightly written that line to map.txt. If yes, enter into EDIT MODE, find proper player, click on "Face" and then press "Y" button (default) and set hairstyle to deafult. It should work.

2) SKIN IS DIFFERENT COLOR THAN FACE

Check "config.txt" in player´s folder in GDB. (If there is no one, make it) Fix value of skin color as instructions in config.txt say.

3) EYES ARE WHITE OR DOES NOT APPEAR IN GAME

Make sure that you fulfill all points. If it still does not work, download THIS file: http://www34.zippyshare.com/v/66059382/file.html, and put it into FileLoader folder.

4) I AM STUPID

Sorry, cannot help you :D
