It's a little surprising that the manufacturer doesn't have some spare parts kept for repair on older, discontinued models. With that said, it seems that you would need to pull out the broken pieces from the female connectors and replace the male connectors on the grill. Without knowing the exact parts you need, a couple of places to look would be http://www.madisoundspeakerstore.com/grill-fasteners/ or http://www.parts-express.com/wizards/searchResults.cfm?srchExt=CAT&srchCat=821&CFID=3907347&CFTOKEN=10865306
Good luck with your project.
Good luck with your project.