Here's a step by step guide to install fonts.
Let's install, for instance, AC Milan fonts (the golden for home and the red one for away kit).
I suggest to install them with these IDs:
Gold: 349
Red: 350
Both this font IDs can be found in the file zdata10.big in Fifa 2005/data directory. So go extracting 4 files:
Jersey's numbers:
playerkittexobj.texobj463104248046875__texture047454833984375__349.fsh
playerkittexobj.texobj463104248046875__texture047454833984375__350.fsh
Shorts' numbers:
playerkittexobj.texobj463104248046875__texture5455322265625__349.fsh
playerkittexobj.texobj463104248046875__texture5455322265625__350.fsh
Extract them with EA Graphics Editor (it doesn't matter if you decompress them or not).
Then open the fsh files with fshtool. Doing so will create a folder for each file, named as the file itself.
You'll find 3 files in each folder:
0000.bmp -> it's the coloured file with numbers
0000-a.bmp -> it's the alpha file (black and white)
index.fsh -> a generated file with info on the fsh file
Replace 0000.bmp and 0000-a.bmp with AC Milan ones. For example for golden numbers use the files [Milan oro 9 con pieghe] 0000.jpg and [Milan] 0000-a.jpg. Remember to convert jpg files into bmp files before the replacement!
After that double click on index.fsh (opening it with fshtool again) to export the data back from the folder to the fsh file.
Now you have the updated fsh file.
Do this for all the fonts you need to update (the same work must be done for jersey numbers and shorts numbers).
Now you should have 4 update fsh files in Fifa 2005/data folder, right?
To import them back to zdata10.big you must use fifaFS.
To do this first copy the following text in a new txt file:
mountfs $dir_fifa2005$\data\
fshhashing random_only
-r playerkittexobj.texobj463104248046875__texture5455322265625__349.fsh |c, playerkittexobj.texobj463104248046875__texture5455322265625__349.fsh
-r playerkittexobj.texobj463104248046875__texture047454833984375__349.fsh |c, playerkittexobj.texobj463104248046875__texture047454833984375__349.fsh
-r playerkittexobj.texobj463104248046875__texture5455322265625__350.fsh |c, playerkittexobj.texobj463104248046875__texture5455322265625__350.fsh
-r playerkittexobj.texobj463104248046875__texture047454833984375__350.fsh |c, playerkittexobj.texobj463104248046875__texture047454833984375__350.fsh
fix $dir_fifa2005$
Call this txt file "installnumbers.txt".
Then create another txt file called "install.txt" and copy inside it the following text:
fifafs.exe installnumbers.txt
Rename this file as "install.bat".
Now we have gathered all the ingredients to install the new numbers. In Fifa 2005/data directory you should now have the following files:
playerkittexobj.texobj463104248046875__texture047454833984375__349.fsh
playerkittexobj.texobj463104248046875__texture047454833984375__350.fsh
playerkittexobj.texobj463104248046875__texture5455322265625__349.fsh
playerkittexobj.texobj463104248046875__texture5455322265625__350.fsh
installnumbers.txt
install.bat
fifafs.exe
Double click on the file install.bat and it's done!
The last step is to run CC, open the AC Milan window, go on "Kits" and change the field "Jersey No. color ID" to 349 for home kit and goalkeeper kit and to 350 for the away kit and the third kit. Then for the shorts go down to the field "Short No. color ID" and to the same thing as for jersey.
Save and the work is done!
Enjoy!