HIghtemp RTV (the red stuff) grease up the edge of the Fire box. Put a bead on the lid close it up and put a weight in the handle leave it for a day. Remove the weight open the door and trim any excess. Or you could return it to the store and buy a Chargriller Outlaw and not have that issue.
I never met a Cow that I didn't like with a little Salt & Pepper! Certified PORK-A-HOLIC