Open up all of your action sequence/ multiplicity photos in photoshop.
Make the first file (the first in the sequence if action sequence your background. Press CTRL + A to "Select All" then CTRL +C to "Copy". Press CTRL + V in your first or background image to "Paste."
Copy and paste all your layers into one image. Arrange them from start to finish in action sequence. IF doing multiplicity arrange from farthest to closest.
In your topmost layer you will select the subject using the lasso tools, pen tool, or the quick select tool. The better your selection the better it will look. Make sure to include shadows!
Once you have made your selection go to the top and click "Select" and "Inverse." This will select everything except the subject
Delete the Selection. This will reveal the layer below.
Move to the next layer down. select the subject in that layer, including any shadows.
Delete the inverse selection of the 2nd layer. now you will three subjects. Move onto layer three and select the subject. Continue selecting the subject then select-inverse-delete
Once you get down to your base layer your image should be done. You will keep the background of your bottom layer. It should look similar to to the image on the left.