Keyboard shortcuts to rearrange items in a numbered list:

1.  Place your cursor at the beginning of the list item you want to move to another location in the list and press Shift + End to select one line, Ctrl + Shift + Down Arrow to select to the end of a paragraph.

2.  Press F2.

3.  Arrow key to the beginning of the list item where you want to move the text.

4.  Press Enter.

Your text is now in the new location on the list and the existing  numbered item has moved down the list and renumbered itself. 

If you are using the mouse to select text, make sure you are also selecting the ending paragraph mark of the numbered item or you will add the text to the new location instead of moving the text.  If you do not work with paragraph marks showing, you can toggle the marks on and off with Ctrl + Shift + 8.