Sorry Mark - I dont have elements BUT the following should still apply.
Open both images. on one, ctrl a and then ctrl c to copy it. Open the second image and ctrl v to paste the 1st into a new layer.
Open a layer mask and selecting a brush and the colour black, paint out the detail that you DONT want in the 1st picture. This will bring through the detail of the one you do in the second.
If you make a mistake, swap to white and it brings the detail back.
Adjusting the size, hardness, opacity and flow of the paintbrush will help with finer detail
hope that helps