How Do They Change/Modify Photos

Question

I've seen this often, and have wondered how they do the following: how can they paste the head/face of one person onto the body of another, and how do they paste a photo of the same or different person into the same photo? Is there a special program to perform these "tricks"?

Answer 1

Yeah, there's this software called facedub that was made for body swapping. Not only can you put your face onto another body, but the program matches the skin so it looks like the two are one in the same. Google facedub, you'll find it.