Way 1
sudo yum-config-manager –enable epel
sudo yum install -y phpMyAdmin
Reference: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/install-LAMP.html
Way 2
yum –enablerepo=epel install phpmyadmin
sudo ln -s /usr/share/phpmyadmin /var/www/html/phpmyadmin
Reference: http://superuser.com/questions/291230/how-to-install-phpmyadmin-on-linux-ec2-instance