Repair cracked or broken cement roofing tiles by cleaning the crack carefully and filling it with silicone caulk or roofing repair cement. Such repairs are usually easier than replacing the damaged tile. When working on a tile roof, use a foldable extension ladder to reach tiles you cannot reach from a ladder on the ground. Extend the fold of the ladder over the peak of the roof, and use the rungs to distribute your weight to prevent breaking more tiles.
Clean the broken tile with a toothbrush or a fine wire brush. Use a mixture of mild dishwashing detergent and water for cleaning, and rinse the area well. Allow at least 24 hours for the tile to dry before applying the patch, ensuring it has the best chance of adhering and stopping further damage.
If the tile requires replacement, use the curved end of a pry bar to lift the tile above it and the one adjacent to the left. Work carefully so you do not break these tiles in the process. Remove any broken pieces remaining from the damaged tile. If necessary, use a hammer to break away any damaged tiles that you cannot remove when the surrounding tiles are loose. Use pliers to pull any nails remaining in the wood. Install the replacement tile, and then tighten the surrounding tiles back in place.