Check out stylin concepts or go to ebay. I just came from ebay picking up a few parts for my truck and ran across and they had a slew of grills listed. Good Luck!
I wasn't sure what kind of grill you meant, so I found the grills that you cook with, and the type of grills that go in your teeth. I hope that helped. It's local places where you can find grills and grillz.
You can't take the grills off but plug it up and make it really hot then turn it sideways facing the sink and clean it with a scrub brush (or thick towel) and soapy water. The heat helps the food dislodge faster.