Go into your main drive (C/), go to programmes. You'll see the VGHD folder. make a copy of this folder, then rename it VGHD1. Go into the folder VGHD1, click on the red V icon, it'll start another VGHD programme. Now you can right-click on the icon (bottom right of screen) like normal to get the options, or left click on icon to start VGHD. Just make more copies of the folder for more models.
You can have as many as you want running at the same time, it depends on whether your graphics card can handle it. You should be safe with 3 or 4.
Hope this helps