Simply change or reset your MySQL root password by doing the following:

Stop the MySQL server

sudo service mysql stop

Start mysqld

sudo mysqld --skip-grant-tables &

Login to MySQL as root

mysql -u root mysql

Change MYSECRET with your new root password

UPDATE user SET Password=PASSWORD('MYSECRET') WHERE User='root'; FLUSH PRIVILEGES; exit;

Kill mysqld

sudo pkill mysqld

Start mysql

sudo service mysql start

Login to phpmyadmin as root with your new password