MyBB Security Tutorial and Guidelines

"Change mybb_ to your new database prefix."
Wow, really?

Just get http://www.mybbsecurity.net/attachment.php?aid=11 and upload to the root directory, then visit the file (if you get a SQL error, then you're fine). Now visit the config.php file and see if it's updated, if it is, you can then remove the .php file you uploaded.