I don't believe it's possible to change the geometry in a fixed pixel flat panel display.
Just google Panasonic Service Menu or just search this forum and you'll find the method. But educate yourself on the dangers and procedures before going in there - one wrong key press and you can ruin your display. Write down every factory value on every page/window before changing anything so if you screw up, you can return the TV to it's original value(s).
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