BuddyPress.org

hi there how do i go about removing my main header and main navigation bar completely from the buddypress pages? i can remove the header from the activity groups and members general pages but when a user goes to there activity stream messages friends etc the header and nav bar is above them…i want these pages to not have the main header and navigation that is on the rest of my site pages as users have to keep scrolling down to the buddypress pages otherwise. thx