You're almost there! Hopefully this stage will be the end of your process of overcoming your spider phobia! Now that you have been equiped with more knowledge than ever, regarding your mild spider phobia, you'd be able to complete the process and remain brave in the face of spiders.
This bit is the best and worst simultaneously. If the previous sessions have gone well, then this should be an empowering experience for you, however if you find that you can't go through with it, linger on stage two a little longer and come back to try again later.
The key to this step is exposure. Not to say that you need to go looking for a spider, but if you go to places that you know there are spiders, such as the attic, then you'll end up seeing a spider. Using what you know now, and thinking about the way you act, try and control this situation. Before you see the spider, try and work out what you want to do, whether it is grab it in some tissue and throw it out a window or pick it up gently in your hand and place it in the garden.
As you are dealing with the spider, at first it may be helpful to imagine that you are doing something else. For instance, if you are grabbing it with a tissue, imagine you've blown your nose and are throwing the tissue away.
The level of control you can exert by doing this allows you to be in charge, whenever there is a spider near you, so you don't need to be afraid of what it is going to do. Plus, now you can deal with everyone else's spiders too!