Tool that you need for roof repair is a flat pry bar.
1. Insert a flat pry bar under and above the damaged shingle to break the seal.
2. Insert a flat pry bar to two shingles that are above the damaged shingle and loose the seals and take the nails out . See video for more details.
3. After you take the all relevant nails out , you will be able to take the damaged shingle out. You can find these nails under the first shingle that is covering the damaged shingle and second shingle above.
4. Slide the new shingle or tab in place, secure it under the shingle above with at a minimum 1” roofing nail.
5. Once the damaged shingle is replaced, lift the tab up and apply a small amount of roof cement of silicone to help adhere the shingle.
https://m.youtube.com/watch?v=h8zVA1357os
