XML Swap Around

Hi all,

I would just like to say a quick hello before posting my first ever query. I am afriad I have very little knowledge of XML to the point I know what it is and that is about it. I have unfortunately been asked to solve a problem with a large number of xml documents that we hold. We have a Start and End Tage of <FormalStatement> and a Tag that comes after it called <Paragraph> what I have been asked to do is swap the contents of these 2 tags so the <FormalStatment> tag contains the data that is in the <Paragraph> tag and vice versa, can someone please help or at least tell me where I should start.

Thanks
PD