The easiest way to move a waypoint is to drag it over the map. To do this, hold down the ‘Alt’ key, now left click on the waypoint and hold this button down while you move the waypoint to its new position.
You can also change the position of a waypoint by changing the coordinates in the properties window, although this method is more complicated than the previous one.
To copy a waypoint to another place on the map (keeping the original waypoint) first hold down the ‘Control’ key then left click on the waypoint and, holding down the ‘Control’ key and the left button, drag the mouse to the point where you want to create the new waypoint. A copy of original waypoint will be created at the new coordinates.