apt-get update && apt-get upgrade
Step 2: Install PHP 5.6
Install the PHP5.6 repository with these two commands.
apt-get install -y software-properties-common
add-apt-repository ppa:ondrej/php
apt-get update
apt-get install -y php5.6
Step 3: Switch PHP 7.0 to PHP 5.6
Switch from PHP 7.0 to PHP 5.6 while restarting Apache to recognize the change:
a2dismod php7.0
a2enmod php5.6
service apache2 restart
