// Create the function to use in the action hook
function example_remove_dashboard_widgets() {
    // Globalize the metaboxes array, this holds all the widgets for wp-admin
 
    global $wp_meta_boxes;
 
    // Remove the incomming links widget
    unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_incoming_links']);  
 
    // Remove right now
    unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_right_now']);
    unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_primary']);
    unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_secondary']);
}
 
// Hoook into the 'wp_dashboard_setup' action to register our function
add_action('wp_dashboard_setup', 'example_remove_dashboard_widgets' );