If the submitted file is a PDF and you have Acrobat Pro (not just Reader) then just use the Extract files and select the Save as seperate files in the dialog. You'll need to reorder them but that should be a problem.
I think you mean extrac pages, and I don't think that's going to help since the pages are imposed spreads.
I'd make a new layout in ID with single pages, then place the PDF twice for each spread, cropping off opposite halves, then manually shuffle the pages into the correct order (because I don't have a script that can unimpose).
Thanks Peter I appreciate it. You are exactly right. When I extract the pages the covers are sing 8.5x11 but the body pages are all 11x17(two pages on one sheet). Your solution of placeing the documents twice in indesign and just using the bounding box to crop out the uneccessary page seems to be the best way to go about it. Luckily the pamplet is only 8 pages long. I would have been up a creek had it had a lot of pages.