Try Google with Photoshop composites.
Basically, you select both images in Bridge, and go Tools > Photoshop > Load files into Photoshop layers
Then add a layer mask to the upper layer and fill it with black. Paint in the faces you want with white in the layer mask, and use the move tool to align with the bottom layer.
thank you for your help. I have managed to load Bridge but how do I select 2 images to go into Photoshop I only seem to be able to select the one preview photo. Thanks.
Managed to select the 2 photos now, mow on to the next part :-)
Which layer mask do i need, there are 3 - Reveal all, Hide all or From Transparency
There’s a mnemonic for layer masks:
‘White reveals and black conceals ‘
Create a new layer above the other two, and fill it with a bright colour like red. Now add a layer mask. It doesn’t matter which one, but most people just select the layer, and click on the layer mask icon at the bottom of the layers panel (third from the left).
Now select the paint brush, and with black as the foreground colour, start painting in the mask. (you can tell whether the mask or the layer is selected because one will have a double line around its icon in the layers panel. You’ll start with the image covered in red, but as you paint with black (black conceals) the red will disappear showing the contents of the underlying layer.