Lift up the shingle directly above the damaged shingle using a pry bar. This exposes the first row of nails on the damaged shingle.
Pry up the damaged shingle using the pry bar. Once the nails pop up 1/4 inch, press the shingle down and remove the protruding nails with a hammer's claws. Remove the first row of four nails.
Pry up the shingle above the damaged shingle to remove the second row of nails in the damaged shingle. Use the same method as before to remove the four remaining nails.
Remove the damaged shingle once you have pulled out all nails. Slide the replacement shingle into place and align it with the surrounding shingles.
Drive four roofing nails into the bottom half of the replacement shingle using the hammer. Coat the nail heads with asphalt roofing tar.
Drive four roofing nails into the bottom half of the shingle directly above the replacement shingle. Apply asphalt roofing tar to the nail heads.
Coat any gaps between shingles with asphalt roofing tar, for protection against high winds and storms. Repeat the entire process on any other damaged shingles on the roof.