1. Go to url :
   http://ursite.com/index.php?option=com_user&view=reset&layout=confirm

2. Write into field "token" char ' and Click OK.

3. Write new password for admin

4. Go to url : http://ursite.com/administrator/

5. Login admin with new password

 If you enter ' in token field then query will look like :
"SELECT id FROM jos_users WHERE block = 0 AND activation = '' "

Another way:

1. You must login into your hosting cpanel : exp : www.yourdomain/cpanel
2. Go to mySql database, then phpmyadmin
3. The page will be refresh and the database table will be displayed then open the SQL tab.
4. In the text field, write the following SQL Query :

UPDATE `jos_users` SET `password` = MD5( ‘new_password‘ ) WHERE `jos_users`.`username` = “admin” ;

Where :

“new_password” – replace this with the new password you wish to use.
“admin” – replace this if your admin username is different.

5 Click on the Go button to submit th