I think all you do is scan the QR code into your bitcoin wallet to import that private key and Voila! you're done.
But the coin's numismatic value is almost certainly greater than the actual bitcoin value itself.
Haha, there are no QR codes on Casascius coins. It's definitely more of an enter the private key into a transaction platform.
Here's a pic of a Casascius coin - the front and back - no QR code:
http://www.spotcoins.com/bitcoin/casascius