change default wordpress message

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($wp_meta_boxes['dashboard']['normal']['core']['dashboard_incoming_links']);   
//$wp_meta_boxes['dashboard']['normal']['core']['dashboard_plugins']
    // Remove right now
    unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_plugins']);
    unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_quick_press']);
    //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' );


if ( !current_user_can( 'edit_users' ) ) {
  add_action( 'init', create_function( '$a', "remove_action( 'init', 'wp_version_check' );" ), 2 );
  add_filter( 'pre_option_update_core', create_function( '$a', "return null;" ) );
}

add_action( 'init', create_function( '$a', "remove_action( 'init', 'wp_version_check' );" ), 2 );
add_filter( 'pre_option_update_core', create_function( '$a', "return null;" ) );

remove_action( 'wp_version_check', 'wp_version_check' );
remove_action( 'admin_init', '_maybe_update_core' );
add_filter( 'pre_transient_update_core', create_function( '$a', "return null;" ) );
add_filter( 'pre_site_transient_update_core', create_function( '$a', "return null;" ) );