For those who wants to access the icon files directly, the full location is:
If you get into it with Finder, you'll see the icons. But if you're quite familiar with working on terminal and the names of the icon you need, you can easily copy them to the location you want thru terminal.
/System/Library/CoreServices/CoreTypes.bundle/Contents/Resources
If you get into it with Finder, you'll see the icons. But if you're quite familiar with working on terminal and the names of the icon you need, you can easily copy them to the location you want thru terminal.