Magento - How to change admin URL

The username, password may sometimes be guessed, so it is recommended to change URL to access admin area of magento site.
Magento facilitate to add URL for admin while installing it. What if you already installed and now want to change it.
You can change it from here.
open app/etc/local.xml in your favorite editor.

change the "admin" text enclosed in <frontName> tag.
You are done!!!