Add it to functions.php
/**
* Remove a top level admin menu in Dashboard
*
* http://codex.wordpress.org/Function_Reference/remove_menu_page
*/
function remove_menus(){
remove_menu_page( 'edit.php' ); //Posts
remove_menu_page( 'edit-comments.php' ); //Comments
remove_menu_page( 'tools.php' ); //Tools
}
add_action( 'admin_menu', 'remove_menus' );How to remove left menu items in Dashboard.
For removing submenu item: http://codex.wordpress.org/Function_Reference/remove_submenu_page
Below removes Posts, Comments, and Tools.
/**
* Remove a top level admin menu in Dashboard
*
* http://codex.wordpress.org/Function_Reference/remove_menu_page
*/
function remove_menus(){
remove_menu_page( 'edit.php' ); //Posts
remove_menu_page( 'edit-comments.php' ); //Comments
remove_menu_page( 'tools.php' ); //Tools
}
add_action( 'admin_menu', 'remove_menus' );
Default WordPress Dashboard left menu
Edited WordPress Dashboard left menu
http://codex.wordpress.org/Function_Reference/remove_menu_page
As a plugin: http://premium.wpmudev.org/blog/how-to-remove-menus-from-the-wordpress-dashboard/