Step 1) Peel the backing from each of the actual stamps.
Step 2) Each set comes with an image sheet. One at a time, remove the backing from an image. The part you exposed is sticky and is ready for your stamp to be adhered to. Carefully press the back side of the stamp onto the image. It's easy to see exactly how it fits on.
In the picture below it shows the backing removed from the image and it's ready to have the stamp adhered.