The steps:

First you need to edit the file in: /etc/hostconfig and remove the line

Since this is a system file I advise you to open it with nano in terminal:

1. Open Terminal
2. sudo nano /etc/hostconfig
3. Enter your password if you’re not authed yet.
4. Delete the following line: “MYSQLCOM=-YES-”
5. CTRL+X (This is the command for closing NANO, Enter the “Y” key to save the file and exit nano).

Second step:

Make sure MySQL is not running.

1. Open Terminal and copy and paste and run the following commands:

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

MySQL is now removed from your MAC.