The easiest way is the Lost your password? link on the login page, which emails you a reset link.
If email isn't working, reset it from the database via phpMyAdmin:
- In cPanel open phpMyAdmin and select your WordPress database.
- Open the
wp_userstable and click Edit on your user. - In the
user_passrow, choose MD5 from the Function dropdown, type your new password in the Value box, and click Go.
You can now log in with the new password and change it again inside Users > Profile. Not sure which database your site uses? Check wp-config.php in File Manager, or open a ticket for help.