Now that you feel comfortable with the "shapes" from the first three examples, we're going to apply them across all six strings using a pattern of two steps forward, one step back. These will build up stamina in your fretting hand so that you can continue to play using this technique over long passages without losing the legato sound or tiring out.
As always, start slow and build up the tempo slowly. Apply the pattern to all three shapes taking breaks in between each shape. It is important not to burn yourself out on the exercise or injure your wrist!