Is there a good way to change UPPER CASE html tags to lower case, across a whole document?

So, I've got a bunch of markup-pages delivered that I am supposed to style. Problem is that tags are all in uppercase, even though the doctype declares it as 开发者_JAVA技巧xhtml. Not only is it ugly and hurting my eyes, it's also wrong, isn't it?

Is there a good way, perhaps a coda (my preferred tool), plug-in, or online service that can do this for me? Or can you do a regexp search-and-replace in coda, and if so, how? (I'll be the first to admit that regexp isn't my cup o'Java.)

You could try figuring out how to do it in RegExp (something a little like /<([^>]*)>/g would be a bit too simplistic, but its a start) but that still presents problems. Coda's RegExp just does find-and-replace so I don't think you'd be able to do a "toLowerCase()" on each item found before replacing with Coda - you'd have to use some scripting language.

Another option is to download the W3C's Tidy application which I believe has "to uppercase" and "to lowercase" options, though I've not used it. It's here: http://tidy.sourceforge.net/#binaries (hasn't been updated in a while)