Ok, this is an advanced beginners tutorial in Gimp.

Goal: Add a person (element) of one photo to another photo a bit like a ghost...

In order not to divert from the process i have used only symbolic 'photos'. This is the 'background' the photo, the ghost shall be added to

This is the photo with the 'ghost' in it

(Just seen it looks a bit like the Japanese flag.. sorry Mr. Fuji )

First open the picture background and than open the picture ghost as a layer!!

I am German and i will not load the English version of Gimp just for this tutotial but the postion of the menue item and the shortcuts are the same.

Your layer section should now look like this

Now we have to remove everything from the Ghost layer (I named the layers this way - this is not a Gimp extra ) that is not the Ghost. For that we make a selection of the ghost (person, element), invert the selection and than delete the selection.

We now should see something like this:

Quite nice but the 'Ghost' will not be in the right place and size. We can move the selection with the move tool

And than scale it with the (have a guess... ) scale tool

The result should be quite ok and look like this

The only thing we miss is the 'Ghost' effect. We can adjust this with the transparency value of the Ghost layer (in this example 49.1%)

That's it.

The end result

We can now save this picture as a JPG (or what we like) which will give us what we want.