To install roof shingles, start by laying tarps on the ground to catch debris. Remove old shingles using a roofing fork or shovel. Install underlayment and new flashing on the roof. Cut your shingles to size if they're not pre-cut and start laying them from the bottom edge of the roof. Overlap each metal piece by at least 150 mm (6") and use asphalt plastic cement under each section of overlap.