Start raster graphics editor. It needs to be powerful enough features simple, for example, Paint or Mtpaint, may not be enough. Useful, for example, the editor GIMP, which combines an extensive set of features, free and small download size (20 megabytes).
Edit the picture with the background: "File" - "Open". Select the file then press "OK". Then save this image under a different name: "File" - "Save as". Select the folder to save the file. In the "Determine file type" screen, leave the default "By extension". Enter a new file name together with a dot and JPG. Press "OK".
The way above, open the file with a portrait to place over the background. The person must be photographed in full growth. Against the background of what he originally filmed, no matter.
On the toolbar, GIMP select tool "select the shapes in the image". On the button is a stylized drawing of scissors, which is where the sine wave. In other editors this tool may be named differently, and the corresponding button to have a different view.
Put points on the contour of the image of man. The line between them will be pulled through automatically. Closing the loop, click on its first point.
Move the mouse point so that the twisting line corresponds as nearly as possible the contour of the portrait. If necessary, add intermediate points and also move them.
Make one mouse click in the middle of the selection. The dots will disappear, and the contour will remain.
Copy fragment to clipboard: Ctrl+C.
Navigate to the file with the background and place a picture of a man on it: Ctrl+V.
Move the portrait of a man in the background.
If it turns out that human representation is too big or too small for the selected background, start the dialogue, scale: "Tools" - "Transform" - "Zoom". If you change the size, click "OK" button in the zoom window.
Press R and then click the mouse in the background. If necessary, similarly place on collage portraits of several people. Then save the result by clicking Ctrl+S.