Previously I mentioned an excellent Core Data code generator tool called Mogenerator and a nice getting started tutorial.
Here’s another Core Data tool that is nice to have around called MomDec from Tom Harrington.
Momdec allows you to take a compiled Core Data model and turn it into a xcdatamodel or xcdatamodeld file that you can the use with the Xcode Managed Object model tools.
You could also use the resulting files with Mogenerator.
You can find MomDec on Github here.
A nice tool to have lying around.