Using XSLT to do a search & replace

Hi,

I have a XML file that I want to transform. I want to be able to do a
search & replace on elements in the XML and replace them. For example:

Replace <para> with [ParaStyle:para]
Replace <text> with [ParaStyle:text]

etc...

I would like to have all the search & replace in one file which is
called or imported by the main script. Does something like this already
exist? I've been searching the internet but can't find a nice example.