dude you need to open dt04 with afs explorer then unzlib it with the same program next you need to save it on your desktop as a .bin file once you do that open the unnamed_32 with any hex editor program i have a tutorial for renaming balls but it's in spanish but you can see it and just follow instructions on screen you can change boots names doing the same process i recomend to watch it on youtube at 720 hd and expand the video for better view
here's the video
http://www.youtube.com/watch?v=6LHzOvGJp0E
nop dude you run out of luck, sorry!!!
thank you luigi, now i can try to edit the team names... seems to be kind of hard thou