I found this video on replacing the rear main seal on an LS6 engine, and thought it interesting enough to want to keep a link to it. It's not in a Corvette, but it shouldn't matter much for the seal itself and the rear plate gasket.
https://www.youtube.com/watch?v=irUX9dS3PZ0
https://www.youtube.com/watch?v=irUX9dS3PZ0