how can I rename an apron pac file if two separate aprons have the same ID number?

[909990999900]

specifically I'm wondering how to rename my apron pac file for the royal rumble 2004 arena. it shares the same apron number as another modded arena wrestlemania x8. since I like x8 more I've just used that apron but if I open rr2004  it will have wrestlemania apron.  the apron number is 000034.pac. I tried manually renaming it manually to some random number but it crashed my game when I tried to load the arena after setting the new apron number in wrestle minus.  how do you legitimately change the number for an apron PR any file so it doesn't clash with another? any help would be greatly appreciated.