1.You have to increase the size of the background.
Go to Image--Canvas Size and increase the size of the white parts.
2. You have to cut the half of your picture.
Select the half with 'Marquee tool' then right click and click 'Layer via cut'.
3. You have to increase the picture.
Go to Edit--Free transform. Then drag the corner pushing 'shift'.
4. You have to attach the picture.
Select 'Move tool' and control the location of picture.