Which library files should I delete? Do I rename the file I'm keeping as just plain icon.library?
Correct. You want the correct one for your processor from @Matthey's link (
IconLib_46.4.412.lha), rename it to just "icon.library", and stick it in LIBS:.

Edit: you should also get the C: tools from the Aminet version (
Aminet - util/libs/IconLib_46.4.lha ), as well, and stick those in your C:. You may want to play around with them, they let you do things like make outlined text, or you may not. But doesn't hurt to have them.
