Every now and again a MySQL root password may have been forgotten or undocumented along the way, but that does not negate the need to access the MySQL server. There is a way to gain access to the MySQL server to change the password for root and eventually log in as root.
Applies to:
CentOS / RHEL / Scientific Linux / Oracle Linux / Fedora
Stop the MySQL service
service mysqld stop
Start MySQL in safe mode
mysqld_safe --skip-grant-tables &
Logon as root
mysql -u root
Use the MySQL database
use mysql;
Reset the password
update user set password=PASSWORD("mynewpassword") where User='root';
Flush the privileges and quit
flush privileges; quit;
Restart
service mysqld start
Logon with new password
mysql -u root -p
Source(s)
http://www.rackspace.com/knowledge_center/article/mysql-resetting-a-lost-mysql-root-password