Phoenix.
Make a duplicate layer of your picture.
Use the selection tool to make say a square in the top half of your pic.
Go to select/feather and set the level to 50%
Then select inverse
Use the eraser at about 40% opacity and erase the bottom half of the pic.
Make the underlying layer (the duplicate youmade non visible by clicking off the eye icon.
You should get something like this.
Hope this is some help