repair for damage I caused during ice damming removal...

Hello, I'm a first time home owner. We have lived in our home for 3 winters now. It is a 1965 ranch with an attached one car garage. This year was the first time we had any water come in the house from ice build up. In what was a "rookie move" I panicked and took the hammer and pry bar to the ice. I ended up tearing a few tabs off the shingles. I think I have a good idea of how to prevent the ice damming next year just by reading all of the ventilation tips you fellows have provided. My question has more to do with repairing the damage. When I look around my neighborhood I see that most of the houses have a metal flashing/shingle across the leading edge of the entire house. Usually 2 feet or so depending on the roof pitch. I would like to retro fit this on to the front edge of my roof without removing any thing more than the first few courses of shingles. Does this sound feasible and if so would you have any suggestions or tips. The roof is about ten years old and in ok shape, however if I'm just wasting my time with the repair, I will consider redoing the roof. Thank you in advance for your time and consideration. Paul G. Glens Falls NY