fatal error

Our site is, http://www.academicathleticism.net

We installed the BP Social theme with an OnDemand WP theme we have and get the fatal error below and we are now unable to access the dashboard, can you assist us?

Fatal error: Cannot redeclare bp_dtheme_ajax_querystring() (previously declared in /home/academc/public_html/wp-content/plugins/buddypress/bp-themes/bp-default/_inc/ajax.php:20) in /home/academc/public_html/wp-content/themes/bp-social/_inc/ajax.php on line 63