jQuery/javascript replace tag type

Question

Is there an easy way to loop through all td tags and change them to th? (etc).

My current approach would be to wrap them with the th and then remove the td, but then

Answer 1

document.body.innerHTML=document.body.innerHTML.replace(/(\<td\>)|(\<td\s)|(\<\/td\>)/gi,function(x){return x.replace("td","th");})

Answer 2

Slight addition to @GlenCrawford answer, to also preserve inner text with the line:

newElement.text($(value).text());

All together now:

$("td").each(function(index) {
  var thisTD = this;
  var newElement = $("<th></th>");
  newElement.text($(value).text());
  $.each(this.attributes, function(index) {
    $(newElement).attr(thisTD.attributes[index].name, thisTD.attributes[index].value);
  });
  $(this).after(newElement).remove();
});