This id what you NEED (in red)to change, the rest is up to you
// ****** DATABASE NAME ******
// This is the name of the database where your vBulletin will be located.
// This must be created by your webhost.
$config['Database']['dbname'] = '********';
// ****** MASTER DATABASE SERVER NAME AND PORT ******
// This is the hostname or IP address and port of the database server.
// If you are unsure of what to put here, leave the default values.
$config['MasterServer']['servername'] = '*************';
$config['MasterServer']['port'] = ****;
// ****** MASTER DATABASE USERNAME & PASSWORD ******
// This is the username and password you use to access MySQL.
// These must be obtained through your webhost.
$config['MasterServer']['username'] = '**********';
$config['MasterServer']['password'] = '**********';
Any problems let me know