add_action('init', 'init_remove_support',100);
function init_remove_support(){
$post_type="your post type";
remove_post_type_support( $post_type, 'editor');
}
place it to your themes functions.php
add_action('init', 'init_remove_support',100);
function init_remove_support(){
$post_type="your post type";
remove_post_type_support( $post_type, 'editor');
}
place it to your themes functions.php