Cutting and merging in Photoshop

First I used the magic wand tool (W) to select the back ground on the left side, I then held shift to select the centre background and the right side. 










I then selected 'Inverse', this reverses the selection. 

I then copied and pasted the selection to the background. 

I then went to edit > transform > scale. 
I held down 'shift' whilst dragging the corner of the image to keep it scaled. 
I then noticed an irritating thin white boarder around the dresses. 

I went back to my original dress later, clicked 'modify' and then 'contract'. 

I chose 3 pixels and then continued to copy and paste the dresses to the background. Below is the result. 

As you can see the highlight around the dress is gone. 













I then proceeded to clear any blemishes around. Below is the finished result.