User Name and Password are the required fields if you want to log in the Magento admin. And it is the huge trouble if you forget one of them. Therefore, resetting admin password is very essential to every store. With Magento 2, “Forgot your password” link is available to click, then a temporary password can be sent to the email address that is associated with the account immediately. Let do the following steps to reset your admin password in Magento 2.
Go to phpmyadmin and copy the following sql query:
UPDATE admin_user SET password = CONCAT(SHA2('xxxxxxxYourNewPassword', 256), ':xxxxxxx:1') WHERE username = 'admin';
xxxxxxx character sequence is a cryptographic salt.
it is saved in
<?php return array ( ... 'crypt' => array ( 'key' => '525701df74e6cba74d5e9a1bb3d935ad', //cryptographic salt ), ...
Forgot Your Password?link.
Ref: Magento 2 user guide
It comes to the end of tutorial: How to reset admin password in Magento 2.