bbp_remove_roles()

function bbp_remove_roles() {

	// Remove the Forums roles
	foreach ( array_keys( bbp_get_dynamic_roles() ) as $bbp_role ) {
		remove_role( $bbp_role );
	}

	// Some early adopters may have a deprecated visitor role. It was later
	// replaced by the Spectator role.
	remove_role( 'bbp_visitor' );
}