1. Slip a flat pry bar under the damaged shingle and press down to pop out the roofing nails.
2. Slide the new shingle up into place. Be sure to align with the shingles of either side.
3. Carefully lift the upper shingle and secure the new shingle with roofing nails.
4. Fix a curled shingle by applying a dab of roofing sealant under the corner with a caulking gun.
5. Weigh down the curled shingle with a brick or concrete patio block. Be careful not to get sealant under the brick.
6. Fix a cracked shingle by gently lifting it and applying a think bead of roofing sealant beneath it.
7. Apply another bead of sealant along the top of the crack and evenly spread it with a putty knife.
8. Hide the repair by sprinkling the sealant with colored shingle granules gathered from the rain gutter.