[jQuery] replaceWith()

[ProfCrazyHorse]

I want to replace one element with another, and keep the element
contents intact.  For example, here, I'm replacing all h2 elements
with h3's:

$("a #replaceWith").click(function () {
   var h2Text = $("h2").text();
   $("h2").replaceWith("<h3>" + h2Text + "</h3>");
});

I have two questions.

First, how can I do this more simply?  I tried the following, but $
(this) refers to the anchor tag and not the h2 selector.  Is there a
way in jQuery to refer to the selector, i.e. $("h2")?

$("a #replaceWith").click(function () {
   $("h2").replaceWith("<h3>" + $(this).text + "</h3>");
});

My second question:  Is there a method more appropriate than
replaceWith to replace certain elements on the apge with others?

Thank you!