If you can get safely to the damaged area,you would need to use a flat bar and lift the nails out of the sorrounding shingles to remove all the torn and broken shingles as well as the ones that the new shingles need to go under.In reality you should hire a roofer or handyman to make sure it is done right.If you were somewhere near Boston,MA i could help.
steve R, November 2010
