Double click on the photo so it is activated and you see the picture tool tab at the top (pink). Copy your photo (Ctrl c) and Past (Ctrl v) so there are two photos.
Double click on one of the photos so the picture tool is activated (it is the pink tab sticking up at the top) and go to the color drop down choosing the black and white option.
Double click the other photo so the picture tool is activated. Click the remove background icon.
Click on the black and white photo and position it to the top left corner. Do the same thing to the second photo with the color.
Finito. Pretty cool you can do this in Word (only 2010).