It's really not all that difficult so I thought I'd do a quick tutorial on how I accomplished it (as I'm sure there are other, more efficient ways of doing it.)
|5. Once you're done, you'll have your 7 layout layers. They should appear in reverse order with the last photo appearing in the top of the layers palette.|
I know my instructions could be better so if you have any questions on how I did it, just let me know!