Log in to your admin cp: [yourvbbdir]/admin/index.php
Choose "Back-up Database" from the menu at the left. Then press the button "Do Backup" And download the backup (something.sql) to a save place on ur hard drive. Next install PHPMyAdmin on ur destinated server where u wish to run vbb on. (
http://www.phpmyadmin.net/index.php?dl=9)
Next, go to your phpmyadmin directory, (i assumed you created a database) and search for the string "Or Location of the textfile" Press the button "Browse" under that string. Select ur backup (something.sql) and press "Ok". This may take a while..
Good luck!