Ok so, idk if this will help with anything but heres this simple short example:
1) Go Here to open the Config
Code:
C:\Program Files\Steam\steamapps\common\call of duty black ops\players\config_mp.cfg
2) When in the Config_mp Press Ctrl+F to search
3) Type "CUSTOM 6" into the search box.
4) Then the code below will appear
Code:
seta prestigeclass1 "CUSTOM 6"
seta prestigeclass2 "CUSTOM 7"
seta prestigeclass3 "CUSTOM 8"
seta prestigeclass4 "CUSTOM 9"
seta prestigeclass5 "CUSTOM 10"
So Then you can just change the names, Save it, And there ya go