Cakephp admin url routing not working -

i have developed large website in cakephp. on development time admin url site_url/admin. client wants lc_admin. change prefixes in core.php file when tried access page shows me error lc_admin_index() action not defined. because actions admin_index , on.

to solve issue tried code below

router::connect('/lc_admin/:controller', array('action' => 'index', 'prefix' => 'admin', 'admin' => true)); router::connect('/lc_admin/:controller/:action/*', array('prefix' => 'admin', 'admin' => true));` 

but old url called site_url/admin working. , want new url accessible.

if want direct route path keyword use simple. route path

router::connect('/lc_admin',array('controller' => 'admin', 'action' => 'index'));