- 1). Place a sturdy ladder into position so that you can safely climb it and easily get up onto the roof. Climb up the ladder and onto the roof.
- 2). Remove any left-behind or damaged shingle pieces from the area of the missing shingle. Carefully bend up the bottom edges of the two shingles on the two rows above the missing shingle, using a pry bar. Pull out any nails or staples left behind from the missing shingle, using the claw of a hammer.
- 3). Cut a replacement shingle to size, if necessary, using a utility knife or a pair of tin snips. Slide the replacement shingle into place.
- 4). Drive four roofing nails into the replacement shingle to fasten it, using a hammer. Drive a nail above each of the slots between the shingle tabs, and one nail on each side of the shingle, approximately halfway down the shingle.
- 5). Apply roofing cement to cover the nail heads, using a putty knife. Apply roofing cement also on the undersides of the raised shingles, and press each of the shingles down.
Source...