Warped or bent floppies

I have a few floppies, both 8-inch and 5.25-inch, whose outer sleeves have been warped or bent due to various reasons over the years. Although it appears that the inner, flexible media are OK, I am reluctant to try to read and copy these without taking some sort of precautions. When I try to manually rotate the inner media, it is either very difficult or impossible without doing some harm to the floppy. (Usually, you can do this manually with only a little effort.) I worry that putting them into a drive may totally destroy the floppy. Some of these floppies (especially the 8-inchers) are up to 20 years old and contain what I now consider to be valuable material. I have successfully read and copied other floppies of the same vintage (and probably same origin) as these warped ones with no problems. So, what do I do? Is it conceivable to open and remove the inner media from the warped sleeves? Should I just try putting them under a pile of books to see if the warps decrease? Any ideas or practical experience with this would be greatly appreciated. Just for reference, in case the particulars help any, the 8-inch floppies are single-sided, single-density and were written on a DEC RX01 or equivalent. Most of the 5.25-inch floppies were written on an Apple II. Thanks, Dave