How to Reset the Root Password of MySql in Linux

Resetting MySQL Root Password: Red Hat and CentOS

If you've forgotten your MySQL root password (or are involved with some nefarious activity), here is how you can reset that password on a Red Hat (RHEL) system or a CentOS system:

Stop MySQL:
root#  service mysqld stop
Start MySQL in safe mode:
root#  mysqld_safe --skip-grant-tables &
Log into MySQL as root:
root#  mysql -u root
Reset the password:
mysql>  update mysql.user set password=PASSWORD("YourNewPassW0RD") where User='root';

mysql>  flush privileges; exit;

Log out of MySQL and stop the Safe Mode:
root#  service mysqld stop
Start MySQL in the normal mode:
root#  service mysqld start
Log into MySQL with your new password:
root#  mysql -u root -p
Enter password:
mysql>

The above info is for a Red Hat system, CentOS, or Scientific Linux setup.  If you need to do this on a Debian system, check out this post.

Reference Link
http://gnuski.blogspot.com/2012/02/resetting-mysql-root-password-red-hat.html
http://blog.applegrew.com/2012/02/how-to-reset-the-root-password-of-mysql-in-linux/
http://crashmag.net/resetting-the-root-password-for-mysql-running-on-rhel-or-centos