First you to https://www.topazlabs.com/downloads then download the software and install. Once installed, there will be an icon on the screen, and it's also integrated into photoshop.
Here you will learn how to use simple jigsaw puzzles. Result
First you open the background image in photoshop, then go to File> Place to insert the image you want to join, now it will insert the model image into a smart object, you should switch to the regular layer by selecting Brush ( B) and paint on that layer and click OK.
Next is the background layer, select the layer you want to split, choose Filter> Topaz Labs. Topaz software will open.
Now select the blue brush to paint around the model's border.
Continue filling or select the fill tool to pour the green color into the area to be retained, red to the drop.
Then click on the apple image above to preview and click on COMPUTE MASK to separate the background, finally click OK is complete: D
So we cut it later, it will create a copy layer in photoshop, hide the layer below, and use the Transform tool to adjust the size of the image to fit offline.
Continue to create the shadow for the Virgin, duplicate that layer (Ctrl + J) and rotate the layer back and reduce the opacity to 30%.
That's it, wish you made many beautiful pictures thanks to this tool.
You can see more detailed video tutorials here.
PSD file for you to reference and try https://drive.google.com/open?id=0BwLHOs9x3AnATWlxUW1VdXM2clk