How to change joomla admin login username & password

1. Go to phpmyadmin
2. On the left side of tables look for jos_users table & click it.
3. On the data you want to change click on the edit icon(small pencil icon).
4. Change the username you want to edit.
5. For Editing the password choose MD5 on the drop down box at left side of password written then change the password you want.
6. At the bottom then click Go button.

Now u are done.

If the above doesn't work. Follow the following steps:

SQL code (Sites running on Joomla 1.6.xx)

INSERT INTO `jos_users`
(`id`, `name`, `username`, `email`, `password`, `usertype`, `block`, `sendEmail`,
`registerDate`, `lastvisitDate`,`activation`,`params`)
VALUES ('40', 'Administrator2', 'admin', 'your-email@yourdomain.com',
'd2064d358136996bd22421584a7cb33e:trd7TvKHx6dMeoMmBVxYmg0vuXEA4199',
'Super Administrator', 0, 1, '0000-00-00 00:00:00', '0000-00-00 00:00:00',"","");
INSERT INTO `jos_user_usergroup_map` (`user_id`,`group_id`) VALUES (40, 8);

SQL code (Sites running on Joomla 1.5.xx)

INSERT INTO `jos_users`
(`id`, `name`, `username`, `email`, `password`, `usertype`, `block`, `sendEmail`,
`gid`, `registerDate`, `lastvisitDate`)
VALUES (NULL, 'Administrator2', ' admin ', 'your-email@yourdomain.com',
'd2064d358136996bd22421584a7cb33e:trd7TvKHx6dMeoMmBVxYmg0vuXEA4199',
'Super Administrator', 0, 1, 25, '0000-00-00 00:00:00', '0000-00-00 00:00:00');
INSERT INTO `jos_core_acl_aro` VALUES (NULL, 'users', LAST_INSERT_ID(), 0, 'Administrator2', 0);
INSERT INTO `jos_core_acl_groups_aro_map` VALUES (25, '', LAST_INSERT_ID());

NOTE: The above code has jos_ as the table name’s prefix (Joomla’s default table name prefix). If you changed this prefix when you first installed Joomla, you will need to change jos_ to the prefix that you used.

After inserting these statements, you’ll be able to log in to Joomla with these new login credentials:

Username: admin
Password: secret

After u login plz change the password or username through backend.