There are a couple of types of patio screen doors, but the main type of screen door is hung on the outside and has rollers or glides located at the bottom and top. These are a simple door to remove and install so do not be intimidated by the job. All it will take is a few simple tools and a bit of patience to get the job done right. It is a good idea to have a can of spray lubricant such as WD-40 and a flat headed screwdriver. Again, this is not a difficult job to do, and since the door is located on the outside, it will only make it easier to work with.