101 roofs, that is!
Make sure the sky is clear...for a few days.
You need pry bars, shingle removers, hammers, and a bunch of hammerheads (a good crew of muscle bound pals)
Keep going through the 6 layers of roofing material.
Get down to the plywood.
(in the city it is easier to just throw another roof on, rather than go through hauling the old one through the house. NOT RECOMMENDED.)
At which point you'll realize the whole roof is damned.
The joists are cracked and split. The plywood rotted to flakes. It has to come down. (Cut the joists and plan your escape root.)
You have all your help there. Keep going. The walls are shaky. Take 'em all down.