How to select and reshape an object

To follow this on a Mac, use Command instead of CRTL!

Use the Polygonal lasso tool to select the object. Be sure to include the shadow.

Copy and paste to a new layer. (CTRL C - CTRL V):

Getting rid of the image on the background layer now!

Reselect your selection by CTRL-clicking Layer 1 (this selects according to the layer's transparency!). Click the eye-icon on Layer 1, this makes layer 1 invisible for the moment. Click Layer 0 to select that layer. Choose "Edit->Fill" and push OK.

Your (background image should now look like this:

Ctrl-D deselects and when you click the eye-icon again, Layer 1 is again visible.

The Cross-icon in the tools (or V) will allow you to move the current layer around. So select Layer 1, and type V.

You can now move the world map to any spot you like.

You should, however, refine the cutout to get rid of the orange wall colour. You can do that in different ways, I would either use the eraser tool (E),  the Lasso tool to select the image frame, then invert the selection and delete the wall part or create a mask on for Layer 1.

All depends on the complexity of the object and how the image should be treated afterwards. I would also refine the wall so that the manipulation  (content aware fill) would not be so obvious.

Please note that on the Edit-menu you will find the transform tool to resize the image and to adjust the perspective. And to be perfect, you could also add a shadow, either on a different layer or Layer 1. I would, however, suggest for manipulations like this to work extensively with layers.