Once in the downloads area, find the interface you wish to download and hit the download button, and save it to a memorable place on your computer. After the download is completed you will then need to place the (skinname).zip file into the correct folder on your computer for VirtualDJ to load it, simply copy the .zip file (do not extract) into the VirtualDJ skin folder, this will differ depending on the system you are using, MAC or a Windows based system, below you will find the different file paths for each system
Once the .zip file has been copied into the folder above, you can then load up VirtualDJ. When VirtualDJ has loaded, click on the config button to open up VirtualDJ configuration settings, then goto the Interface tab, located on the left of the window, scroll down until you find the interface you have just installed, and select it. Your new interface should now be displayed on your VirtualDJ software.