Just curious, but why? All you have to do is either a) edit inc_iconfiles.asp and add/delete/change the appropriate icons; or b) replace the current icons with what you want them replaced with.
I was thinking of an interface so that you can have groups of icons (i.e. - seasonal, special events) and simply specify the icon file name rather that overwrite the icons.
Well, just have separate images directories that you can change when you'd like. It would work the same way. You'd just need to be sure you've got all the icons you DON'T change in each of those different directories.