I had both hard dry undercoating and some of the soft greasy stuff. I used a needle scaler on all of it. It was a tiring, filthy, noisy, time-consuming job but in the end I got-r-dun. I went over everything after the scaler with a spray bottle of rubbing alcohol and steel wool, then wiped up the mess with paper towels. A coat of Rustoleum brush-on red primer and then their rattle-can undercoating made it look like new.
