I did the oven trick to get the covers off, but it was still tough after 12-13 minutes at 200 degrees. That stuff is hard and really on there...seems a few years old.
I've decided to just go the old thumb nail route. It's slow and a little rough on the thumb, but works well. This is what I got after 5 minutes of scraping.
Thanks for the advice
Not a bad deal for $300