How to add a buddypress menu item?

Hi

I was following this guide:
http://www.thinkinginwp.com/2009/06/adding-sitewide-menu-items-to-buddypress-site/
And it doesnt seem to work. I uploaded the file to the mu-plugins folder but the changes do not appear.

Maybe the guide is old? Its very fustrating that there are so many old wp guides out there!

I want to add a simple link to another site. Can anyone please point me in the right direction?

Kind regards
Mark