Is there someone who would/could help me change a machine from Vista to XP over the phone? Send me to online instructions, if you can, please. Thanks!
I have some idea, but would like some over the shoulder advice on this, if you would, please.

It's generally not a good idea to post your phone number on the Internet.
If you don't know how to edit your own post, then a Moderator can do it for you.

ok, delete that post, if you can. But point me in the direction of a website or instructions I can follow to do this. Thanks!

You did fine.

XP Clean Install

Machine already has Vista in it. Is this going to work in that situation?

Yes. Instructions are in the link I posted above. Just boot with your XP CD.