Not used Vertrigo but if it is anything like apache2triad then try the following steps.
1. Upload a copy of your site from within the htdocs folder to the root of your webserver.
e.g if your dev site is located \htdocs\test then upload the contents of test to the root of your webserver.
2. Using phpmyadmin export your demo sites SQL database to file.
3. Using phpmyadmin on your webserver delete all the current tables on your database, and then import the sql file you have just created.
4. Edit the following lines of the configuration.php
Path to site as your server sees it eg /data/htdocs/school name
$mosConfig_absolute_path = '%change this%'
eg /data/htdocs/school name/cache
$mosConfig_cachepath = '%change this%';
Name of your live database from step 3
$mosConfig_db = '%change this%';
Your sites address
$mosConfig_live_site = 'www.livesiteaddress.co.uk;
SQL database password
$mosConfig_password = 'password';
$mosConfig_user = 'username';
This is what I have done in the past and works a treat.
Hope it helps.