This is super easy :)
It may seem like a pain, but once you learn how to do it you will have your sanity saved!
The fabulous program this is Photoshop is so wonderful!
A few things you will need:
1. Two or more images, same location, same pose
2. Photoshop or equivalent editing software
3. Layer mask, you can download a free layer mask action at The CoffeeShop Blog or by clicking >here< to zoom straight to it.
So lets get started!
First we have an adorable image, but Oh-no she isn't looking at the camera!
So let's make it look like this!
So now we have our first image open with Miss adorable looking down.
We select file then in the drop down menu we select place. When the new window opens pick the other image with her looking at the camera.
On the new image that you just opened you will want to add a layer mask to it. The layer mask will be white by default. So you will take a large SOFT BLACK brush and paint over anything you do not want to show.
Notice how I blended all the way around his head and on his shirt. If you turned off the visibility this is what the top layer looks like.
So now let's see the finished image.
You can do this with any number of "heads" and images. As well as use the same technique to make one person in multiple spots like this:
Happy Head Swapping!