If you get this error you need to stop mysql first

/etc/init.d/mysql stop

Once done follow the below steps,

$ mysqld_safe –skip-grant-tables &

$ mysql -u root

$mysql> UPDATE user SET Password=PASSWORD(‘your password’) where USER=’root’;

$ /etc/init.d/mysql restart

Now  $ mysql -u root -p

password:  enter your new password here

Done you are in Mysql now