Position the cursor where you want to begin cutting.
Press v to select characters (or uppercase V to select whole lines).
Move the cursor to the end of what you want to cut.
Press d to cut (or y to copy).
Move to where you would like to paste.
Press P to paste before the cursor, or p to paste after.
p
(use v to highlight, y to copy, p to paste)
select with Shift+v and cut with d