Take a sample of a tile in your chimney, or a measurement of the tile, to determine what size tile breaker you need. There are three different sizes. The single 8-inch-by-8-inch breaker is typical for many homes.
Remove the drill bit from your power drill and insert the drill tip into the attachment at the rear of the tile breaker.
Place your tile breaker over the broken tile you would like to remove and pull the trigger on the drill.
Apply firm pressure to the tile with the tile breaker while pulling the drill trigger. Continue until the tile breaks apart.
Use your putty knife to scrape any remaining pieces of tile away from the chimney.