I'm not certain, but I think it involves the use of a third party app called Pacifist, which allows you to get deeper in to the installer than the regular installer interface, and allows for access to the specific elements the installer handles; and allows you to extract the files you need.
Thanks for responding Peter. That's alright...it has been awhile. Someone mentioned using Pacifist as a possible way to find a synth plug in that's missing since I had to re-install Logic8 due to a replaced hard drive. But since then, I've been advised that re-installing Garage Band would probably work. Glad you've got your files back. Peace & Blessings