To Install MySQL 5.6 and phpMyAdmin on Ubuntu just follow the command one by one bellow.
For phpMyAdmin to work, you need PHP to be installed. To install PHP 5.6 😉
add-apt-repository -y ppa:ondrej/mysql-5.6
apt-get update
apt-get install mysql-server-5.6
mysql_secure_installation
apt-get install phpmyadmin
service apache2 restart