-Now Make a copy of your Wings layer. Layer>Duplicate Layer...
-Using the Move tool Drag one of your copies to the top of the screen and one to the bottom, leaving a line about this thick between them. When you have postitioned them correctly merge them together.
-If you are having trouble with this step you might try moving the layers with the arrow keys (hold shift to move them 5px at a time instead of 1).
-Also if you hit F it will change your view of the image and give you more of a border to work with, so you can see where your layer is.
-With the top Wings layer selected Layer>Merge Layers