In newer versions of MySQL it looks like the ‘Password’ field has been replaced with the ‘authentication_string’ field so older instructions online may not work.
Stop the currently running MySQL service:
systemctl stop mysql
Start mysql skipping permissions tables:
mysqld_safe --skip-grant-tables
Then in another terminal run the mysql client:
mysql
Then the following SQL:
UPDATE mysql.user SET authentication_string = PASSWORD('opensesame'), password_expired = 'N' WHERE User = 'root' AND Host = 'localhost';
FLUSH PRIVILEGES;
quit
Return to the first terminal and Crtl-c to end the mysqld_safe process. Then start the normal service:
systemctl start mysql
Try logging in as root again with the new password:
mysql -u root -popensesame
