In order to reset the password details of a user from PHPMyAdmin one need to follow below mentioned steps:
1) Open PHPMyAdmin and Do login into the it.
2) A list of databases will appear. Click your WordPress database.
3) All the tables in your database will appear.
4) Click on wp_users table.
5) Click on the icon for browse or structure.
6) On user_login click browse and find the ID number associated with your login. Go back to the wp_users table. On the user_pass field, click browse and find the ID number associated with your login.
7) Click edit.
8) Click the dropdown menu and select MD5 from the menu.
9) Next to the ID number is a long list of numbers and letters. Select and delete these and type in your new password which one want to use.
10) Click the ‘Go’ button to the bottom right.