AF-S and single focus point are not the same thing.
AF-S is a focus mode, used for stationary subjects.
AF-A, AF-S, AF-C ... you can change them by pressing the auto focus button on the left side of the camera near the lens, and turning the rear command dial.
Page 121 in user manual will explain the different modes
and when to use them.
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Pages 123 to 126 explains the focus points.
Those can be changed by pressing the auto focus button on the left side of the camera near the lens, and turning the front commad dial.
You can move the focus point(s) by using the multi-selector on rear of the camera (up,dn,left,right,OK)
Page 127 explains this.
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I do not use live view, but think you would move the focus point around the same way, page 127.