Other than wallpapers, you will need the proper program to make use of your downloads; For instance, WindowBlinds for WindowBlinds skins, IconPackager, DesktopX and so on. They are all available in 30 day trial versions. However, the best thing to do, if you decide to buy, is get ObjectDesktop, which has almost all of the "skinning" programs in one, inexpensive bundle.
https://store.stardock.com/product.aspx?productid=ESD-SDS-W011
