Jan Dembowski on "Customizing the footer in Attitude theme"

After you've updated your WordPress installation (really, do that first) give this thread a look.

http://wordpress.org/support/topic/remove-or-edit-info-in-footer?replies=28#post-4018588

Start at the top, it'll be easier to get when you do.

Remember, you want to use child theme instead of modifying the Attitude theme directly.

http://codex.wordpress.org/Child_Themes