 and a lot of times contractors will try to sort of tar that in place, but that's a bad idea. What I would recommend is to take out the plumbing vent flashing, and you can do that easily by removing a few shingles in that area. Roof shingles are actually pretty easy to disassemble if you know kind of a trick of the trade. I like to do it with a flat bar that you can slip up under the roof shingle, find the nail, and sort of pry it from side to side, and it'll pop right out.