How do i change an icon?

I have downloaded an icon from deviant art, but the download does not contain any .ico files, it only contains .png .icns and .icontainer, is there a way to change my icons,
Here is the icon incase you want to check it out. Browsing Icons on deviantART

Arc said:

Welcome aboard :)

Upload the .png in ConvertICO.com, it will convert it into .ico online. Download it, save it in a real location, which will not be deleted.

Then right click on the desktop icon of google earth > select properties > click the change icon button . It will direct you to the location where the original icon of google earth is stored. Click the browse button, and browse to the location where you have saved the converted icon. Select it. ok, apply , ok .

Let us know if it worked or not.

Thanks, it worked.