0. Download and install a resource editor (I use Restorator2009)
1. Open your \Windows\system32\shell32.dll with it
2. Go to BITMAPS and change the same numbered pictures with the ones included in the Bitmap folder

The reason I'm not including a shell32.dll file - for now - is that shell32.dll is one of the really important system files for Windows, and if by off-chance yours would differ from the included one, you can mess up the whole system. 

Only replacing bitmaps on the other hand can lead to no harm; even if you mess up the bitmaps' orders that only leads to some graphics issues.