Make a st itch in Photosh op CC or Elements
Open the images. Grab the Lasso tool, set Feather to 10px, then drag a rough selection around a figure. Hit Cmd/Ctrl+C to copy, then go to File>New. Make a new white document and hit Cmd/ Ctrl+V to paste.
Grab the Move Tool, set Auto-Select Layer and Show Bounding Box in the options, then use the tool to position the first figure and resize it if necessary. Then simply select, copy, paste and position the other figures in the same way.
To finish off, go to Layer>Flatten then grab the Dodge Tool, set Range to Highlights and Exposure to 20%, and paint to dodge any areas where parts of the cut-out wall look grey, until they’re perfectly white.