Deleting classes headings styles is troublesome

Im messing around with different templates, i have 2 seperate web pages with different templates, im trying to bring in one part of a template into another, but the styles of the 1st template interfere with the pasted part of another, My question is how do i mass delete all headings and classes (akin to having a new page)its really a pain in the butt to delete all classes, headings and associated styles for every single thing.