Use:
sudo ./unbound-setup.sh
Basically all the shell script does is the following:
/usr/bin/apt-get install unbound
/bin/mv -v /etc/unbound /etc/unbound.dist
/bin/mkdir /etc/unbound
/bin/mv -v * /etc/unbound/
sudo -u unbound unbound-control-setup
Once installed, you must edit /etc/unbound.conf and add your address space and IP addresses as noted in the file
then run /bin/systemctl restart unbound and /bin/systemctl status unbound