I’ve found several interesting icons, but how can I change all icons in just one shot?
Grab New Items: Download Icons
First of all, you’ll need to grab some new icons; I simply love Glass Icon Set provided by Inner Mind Media.
Look Inside: Default Icons’ Directory
Do you know that all of your default Leopard icons lay inside one folder? Even if you don’t know, once you get inside System ▸ Library ▸ CoreServices ▸ CoreTypes.bundle ▸ (control-click) Show Package Contents ▸ Contents ▸ Resources, you’ll know that this folder ever exist.
Safety First: Duplicate Things
Even though I can guarantee that this article will do no harm to your Mac, I still recommend you to do the backup first. The easiest way to do backup is by simply duplicating this folder using keystrokes Command-C after selecting the folder followed by pasting (Command-V) to your backup destination.
Finishing Move: Replace Icons
To replace your default icons, rename the new icons file as follow :
Move all renamed .icns files above, authenticate, confirm replace and enter your admin password. All the files should have been replaced. After you logged off and logged in again, your folders’ display will be changed.