thanks for the prompt replies -
As directed, i googled and found you heat it, then you scrape it, and once it's completely scraped (until there's almost nothing left), you can rub acetone on it and it'll breakdown the last bit of the adhesive.
At least I was able to have a "clean slate" to start working on putting flashing around the nose and sealing the roof. Unfortunately, this is snowballing into a much bigger problem to solve. I thought I had it solved last summer, but the best laid plans...
Anyway, thanks so much for the help!
Take care,
Josh