I've read the guides (a few times

) about the new Search & Replace feature, but sadly, I'm not grasping. I never used the header/footer feature in previous Calibre editions either, so this element is brand new for me. I also know that PDF conversions are riddled with problems.
That said, is there a Regex that can simply remove all headers and footers when doing a PDF to mobi conversion? Don't want to replace anything, just make them all disappear. Any possible way?
Thanks,
Rach