How to reset the root password for mysql:
Stop mysql:
1. service mysql stop

Run mysql with skip grants to be able to login without any password
2. mysqld_safe --skip-grant-tables &

Login as root
3. mysql -u root

4. mysql commands:
mysql> use mysql;
mysql> update user set password=PASSWORD("NEW-ROOT-PASSWORD-HERE") where User='root';
mysql> flush privileges;
mysql> quit

Stop mysql
5. service mysql stop

Start mysql normally:
6. service mysql start

Try to login using your new password:
7. mysql -u root -p