For the thick plastic on HL tanks, you might want to first thin out the track guards (fenders) a little toward the outside with a Dremmel tool....that's normally pretty thin metal and HL plastic is pretty thick. I like to use a micro torch, waving it across the part to be bent and use flat nose pliers or heavy treezers to help twist or bend the part. Be aware of what direction you want to bend and how the damage usually occurs. On the corner fenders, damage is normally caused by the tank backing into something or some debree getting caught in the track and bending it in or even upwards. On the Pershing or tanks with track guard braces, the braces are very often broken or torn loose from the welded spots. Many tank crews just discard the corner sections after they get so bent up. Lots of guys use a hair dryer with good results, but I personaly like a micro torch.