Note: Make sure MySQL is not running.
Copy the following command to the terminal and execute
sudo rm /usr/local/mysql sudo rm -rf /usr/local/mysql* sudo rm -rf /Library/StartupItems/MySQLCOM sudo rm -rf /Library/PreferencePanes/My* sudo rm -rf /Library/Receipts/mysql* sudo rm -rf /Library/Receipts/MySQL* sudo rm /etc/my.cnf