Basically, you will have to mask out areas you want to cut out. Select the Pen tool and draw masks around actors and/or areas you want to remain in the shot.
Break the bodies into several parts (leg, head, torso…) so you will have easier jobs animating the mask. Try to keep those masks as simple as possible. Feather them a pixel or two.
And for God’s sake, before animating your masks, make sure you have the stopwatch enabled on “Mask Shape” :o)) I have animated way too many masks only to find I haven’t enabled the stopwatch.
This seems difficult, but can be done. You may find that you’ll be better off using green screen next time :o)