Run the installer, if it takes more then 15 mins close it.
Run the installer again, it will finish very quickly, but also leave a few packages in a broken state (Media Player will say install failed when you try to install it).
SSH into your AppleTV and run these three commands:
killall -9 apt-get aptitude
rm -f /var/lib/apt/lists/lock
apt-get -y update (if it times out or takes a really long time, press CTRL+C and run the command again)