NTHNer but here is the one I use. It's old but it still works a treat: https://alisdair.mcdiarmid.org/kill-sticky-headers/

    (function () { 
      var i, elements = document.querySelectorAll('body *');

      for (i = 0; i < elements.length; i++) {
        if (getComputedStyle(elements[i]).position === 'fixed') {
          elements[i].parentNode.removeChild(elements[i]);
        }
      }
    })();

I rewrote this to be a little more succinct:

    document.querySelectorAll('body *').forEach(tag =>
      getComputedStyle(tag).position === 'fixed' && tag.remove()
    );

- you can use `forEach()` on the NodeList that `querySelectorAll()` returns

- you can use `remove()` directly on the DOM node you want to remove

Here for an improved version: https://github.com/t-mart/kill-sticky