I got this corny pin lock free from a friend. It's full of Mellow Yellow pre-mix (recent date on the tag so it's still good) so I'm sure it's pressurized. How do I relieve the pressure from this thing so I can safely get the lid off?
http://img409.imageshack.us/my.php?image=dsc01708jd1.jpg
http://img409.imageshack.us/my.php?image=dsc01708jd1.jpg