howto downgrade ed/x/ubuntu 16 php 7.0 to php 5.6

howto downgrade ed/x/ubuntu 16 php 7.0 to php 5.6

install a clean ed/x/ubuntu from ISO but do not add php then

add-apt-repository ppa:ondrej/php
aptitude update
aptitude install php5.6

# verify php
php -v

# verify apache
a2query -m

thanks to