Select a topic on the left side of the help window to see the corresponding help text on the right side of the window.

The up and down arrow keys may be used to scroll the text or move the help topic selection, depending on which “pane” is active.  The active pane is outlined by a black rectangle.  Use the left and right arrow keys, tab key, or click on a pane to select it.

Press command-c to copy the currently displayed scrollable text to the clipboard.