When installing roof shingles, carefully arrange them before you nail them in place. If you need to move a shingle that has been improperly placed or has become damaged, remove it and replace it with another shingle. This should be done right away before any further settling.
Removing and Repositioning Shingles
To move a roof shingle use a claw hammer to remove the roof nails. Take your utility knife or a putty knife and gently push it underneath the shingle to pry it free. Pull the shingle from its place and move it to the side. Replace the area where the shingle was removed with another shingle of similar weight and color.
Replacing the Shingle
Apply adhesive in the middle and in each of the corners of the new shingle. Set the replacement shingle into place by sliding it into the space left by the old shingle. Press down firmly to make sure that it sticks to the roof. Use the claw hammer to place several nails into the shingle to hold it into place. Apply some silicone gel or roof cement to the heads of the nails. This will prevent water from getting in through the nail and stop the roof from leaking.