There's nothing to it. It zooms in and zooms out. The focus mode is determined by the camera, and there's a lens AF override switch that actively disables the internal focus motor. So if the switch is in MF then no matter how you set your camera you can't autofocus.
Also note that because it has an AF-S motor you can override the focus point with one touch. If the camera is autofocusing and can't find the right point or didn't find one at all, or is even still focusing, just grab the focus ring and turn and it overrides the AF for the duration of you holding down the shutter.
Don't touch the contacts or the elements, don't dismantle the lens, and don't hit it with a hammer as all the above void the warranty.