Save this image and open it in PhotoFiltre.
Go to Edit >> Define Pattern.
Go to Image >> Duplicate.
Using the Selection tool on the Polygon setting, select Danny’s face (far left) and copy.
Paste it on top of Tom’s face (second from the left).
Now using the Clone Stamp Tool with my settings, erase away the rough edges.
Go to the Duplicate image and make a selection around Tom’s face now (second from the left). Then paste it on top of Danny (far left) and erase the rough edges.
Now repeat these steps for Dougie and Harry (the other two people) and you should get what I get in the end!