We purchased a house that had been remodeled, including putting tile on the kitchen floor. The person who installed the tile did not do a very good job, and let grout set on some of the tiles along one wall of the kitchen. This is very annoying since this person used white grout, and it is nothing but a dirt magnet. It is also very rough since it is thick in some areas. How can I easily remove the grout from the tops of the tile without damaging the tile as well? Asking this person to come fix it is not an option since we do not want him in this house. Thanks, Amy