There are some tutorials you can find on YouTube to see all the details. Basically, run a hair dryer over the spine several times to loosen the glue, then very carefully slip a knife between the metal plate and the plastic case, and slide the spine off. Remove the excess glue from the metal plate and the plastic case, and then you can turn it around the way it should have been.
To change the interior artwork, search online for a still that you like, print it out (I don't find it makes a lot of difference whether it's printed on glossy photo paper or regular paper), then use a template for steelbook interior art, which is usually linked to any of the YouTube videos you'll find. Send me a message if you want more specifics!
