Copy all the files over to the site root. Edit config.php to reflect the new forum path. There is nothing to change for the database if you are using the same one. Open ACP and change the forum URL in
vBulletin Options -> Site Name / URL / Contact Details.
The only other thing that will need to be done is to change all instances of
http://www.realopinion.com/realboards/ to
http://www.realopinion.com/. If you go over to the vbulletin forum there is a recent thread there somewhere that covers how to do this. If you don't do this then many links will be broken. I recently moved my forum to a new domain and this was something I nearly forgot to do until I started clicking on links and finding they were still pointing to the old location.
Of course there is an easier option, put a redirect in the site root (using htaccess) and leave the forum where it is.
Bob