Auto body repair & detailing: cracked tail light on 2005 Buick Rendezvous, buick rendezvous, junk yard

Question
I have an '05 buick Rendezvous with a cracked tail light that is on the tail gate. My hubby bought a replacement housing unit at the junk yard, but we have no idea how to detach the lens from the fixture so we can fix it. Only one side needs fixed and opposite sides on each unit are cracked. Please help!!!

Answer
The lenses aren't detachable- you have to replace the entire assembly if it had damaged ANYWHERE. If the yard sold you the housing assembly with the idea that you could take a good portion off of a damaged housing and attach it to another with a different area of damage, they were either mistaken, or playing you for a sucker. Bill