make selection of painting and copy onto its own layer. (ctrl+c the ctrl+v)
step 2 of 4
Make selection of wall & window (as before in step 1) move into place using transform tool DISTORT. Do the same with the lady
step 3 of 4
Postion the lady as needed and scale down. Erase all the blue background. In Layers, use the Overlay filter and adjust the Opacity of this layer. Use eraser on the bars of the window(may not see this but good practice)
step 4 of 4
On the layer which is the window you cut out earler goto filter and select 'paint dubs' (use whatever you thinks best)