Removing Herculiner from Body?

Howdy y'all,

My truck came with a sloppy paint job from the previous owner, in which he brushed Herculiner over some of the scuffs on the side panels of the bed. Any tips on how to remove this stuff?

Thank you

 

Back in my high school collision class my buddy had a bed for a T100 with someone else's terrible bedliner on it. We were repainting the whole truck so it had to go. We tried a multitude of paint strippers to no avail. If I remeber correctly the trick we found was to take a propane torch and heat it so it bubled up, then get under it with a sharp gasket scraper. Then sand off any remains. One PITA of a job that got pawned off to the lowerclass men real quick.