Domain Change

[WEBDosser]

If you have the backup file like you said, then upload the files from public_html folder in the backup file to the new hosting accounts public_html folder, then create a database in your hostings cpanel and import the old database backup into that using phpmyadmin or get your host to do it if it's too big..

edit the file config.php inside the includes directory of vbulletin to match the settings from the new database..

basically the same as my first reply.

And don't forget to change the url in members.vbulletin.com to the new domain.