Hi
You could try making disk images of your disks using Disk Utility, but if there are too damaged you may need to try other approaches.
You may be able to get enough of Logic Studio installed such that (once you have updated to the latest versions) you can download the majority of the necessary content via the Logic Pro menu.
I suggest that you re-run the installer, but deselect the Soundtrack Pro content (this is what's on Audio 1, 2 and 3). It would be enough to just install the basic Apps and content only, then download the rest.
Alternatively, try contacting Apple regarding replacement disks, or find a pal with a set you could use (with your own serial number of course).
CCT