Doug’s D453 headers install.

Circle the offending areas with a Sharpie. Then, I'm afraid to say, remove the header. Big pry bars can crush tubes. You'll be able to do a neater and more precise job with it out of the car. Heat the circled area and ding it with a ball peen. In the car, you can't get a clean shot at anything and you run the risk of accidentally messing something else up and REALLY getting mad at yourself. My free advice (which is worth exactly what you paid for it): Just bite the bullet & pull the header. ("Mr. Positive" here: it probably won't be the only time you have to take things back apart. Been there many times!). Good luck and hang tough!