An element or just the name (variable name, address, comment) of an element can be moved to a different position within a LD POU by "drag&drop".

In order to do this select the desired element (contact, coil, function block) and drag it - keeping the mouse key pressed - away from the current position. Thereupon all possible positions within all networks of the POU, to which the element might be moved, will be indicated by grey-filled rectangles.

Move the element to one of these positions and let off the mouse key:  the element will be inserted at the new position.

If you however move the element to the name (variable name) of another element, the name field will be shaded green. If you then let off the mouse key, the previous name will be replaced by the "dragged" one. If additionally address and comment are displayed (options), the copying also will apply to those.