[CentOS] Software Raid Expert Needed

I think you are saying not only do you want to keep the data but also keep
the whole system setup.
Not sure how to do that...however..

If I could back the whole drive up on a third I would just start over and
then move my config files and data over after done.

Hope this tutorial helps, this is how I figured out how to do a raid 1. But
does not cover your exact issue, but since you are new like me, maybe this
will help you.
http://www.bobhoffman.com/wordpress/?page_id=44

Good luck.
Sometimes it is just quiker to start over.