Just wondering how I can update kiln on ubuntu without messing up the installation.
When updating Kiln on Ubuntu, there is no need to shut down kiln first. Installing the new version should automatically handle the upgrade for you.
If that does not work out and your installation gets corrupted, your best bet might be to remove Kiln entirely from your machine with
sudo dpkg --purge kiln, install the newest version fresh, and start your node from a snapshot.
Here's docs for our Ubuntu Distribution as reference - https://gitlab.com/obsidian.systems/tezos-bake-monitor/blob/develop/docs/distros/ubuntu.md