For the record, I've installed it on a Raspberry Pi that I completely forgot was on my network (it's hidden in my comms cabinet on Apple HomeKit duty). The sign of a true geek when you've got RPi's in the house that you forgot where there lol.
It certainly installs/runs but I've not got any USB tuners to test it with so it's over to the community to test.
To manually install;
Download from the link above
run (as root or sudo) dpkg -i <packagename>.deb
If this is the first time TVHeadend has been installed, you might have to run (as root or sudo) 'apt-get install -f' to fix any dependency issues.