ubuntu - Removing MySQL 5.5 Completely - Stack Overflow

do this in all the desktops and servers to get rid of mysql:

sudo deluser mysql
sudo delgroup mysql

So in total do this:

sudo service mysql stop  #or mysqld
sudo killall -9 mysql
sudo killall -9 mysqld
sudo apt-get remove --purge mysql-server mysql-client mysql-common
sudo apt-get autoremove
sudo apt-get autoclean
sudo deluser mysql
sudo rm -rf /var/lib/mysql
sudo apt-get purge mysql-server-core-5.5
sudo apt-get purge mysql-client-core-5.5
sudo rm -rf /var/log/mysql
sudo rm -rf /etc/mysql

ubuntu - Removing MySQL 5.5 Completely - Stack Overflow

If you have any issues, use this:

sudo apt-get purge mysql*
sudo apt-get autoremove
sudo apt-get autoclean
sudo rm -rf /var/log/mysql
sudo rm -rf /var/log/mysql.*
sudo rm -rf /var/lib/mysql

Prepare re-installation of mysql:

sudo apt-get dist-upgrade

Resinstall mysql:

sudo apt-get install mysql-server --fix-missing --fix-broken