You can open the WordPress main database with phpMyAdmin or any other MySQL administration tool and find the users table. The name of WordPress tables has a prefix, and the common prefix of the Wordpres tables is "wp_" by default. So in this example, you have to find the table named "wp_users". You will find all WordPress user accounts by opening the "wp_users" table. After opening or editing each user record, you will be able to set a password for the related user. Find the user_pass in columns and select the "MD5" hash method as the function option of this field. Then change the "value" of this field to your preferred password and click on the "Go" button.