Step 1 : open the image you want to apply the pixel stretch to.
Step 2 : then either select the single column marquee or the single row marquee tool.
Step 3 : now select part of the image with of the marquee tools.
Step 4 : now press ctrl+t
Step 5 : your selection should now be in free transform status. Now just click and move your mouse to either the left or right and kazaaaam!!!! there's your pixel stretch.
More Tutorials: 
