Capitalize on the gauging tape in order to assess the elevation of the opening of the door. Start to determine from the header i.e. the top of the inner framework of your door to the limitation i.e. all-time low of the inner framework. There is a product that is contain with the door when it is obtained called as Z bar, this thing is attached to the steel security door. You will absolutely need to make the most of the hacksaw in order to reduce the Z bar in such a way to ensure that it can fit the opening of the door. You can do this by lowering this bar by maintaining it worrying 3/16 inches a lot less in contrast to the dimension of the structure of the door.