Start by trying to get the left and right images of the first picture to merge into a single 3D image. When you are able to do that, move on to the second image. Go to the progressively larger images until you can freeview an image the size of a standard stereoview, or more if you think it will help you. Expect it to be difficult at first. Expect to be a little dizzy or disoriented. After a while, these unpleasant aspects of freeviewing will go away and you will be able to do it anytime without discomfort.
Here is a picture of the Old Capitol Building in Iowa City, Iowa, for you to practice on.