BuddyPress.org

Well, you need to go through the steps of the section you’re reading, “I’ve used a WordPress theme for my blog with the default BuddyPress member theme”. In essence, you are adapting a non-BP theme to be useable by BP. Your other option is to do what it suggests at the end of that section.

If you need to grab the old default theme files, they can be found here:

https://trac.buddypress.org/browser/tags/1.0.3