How to change prestashop admin panel url address

Firstly installed prestashop change the admin directory name to something random, like admin1389, then you have to login to your website using http://yoursite.com/admin1389

 if you want to change this url:
1- go to your hosting panel or login through ftp 
2- change the admin folder name to whatever you want
3- use your new url address to login to back-office