Replacing Default AI

I have the entire collection of PAI installs in FS2002 and i've noticed that the PAI installer makes it's own BGL instead of replacing default AI. Rather than removing the default AI and using AFCAD to make my own, what is the easiest way to replace the default ones with planes of my own? I can do my own repaints if neccesary. Any help on this would be appreciated. 
