This will be a very short but helpful post.

I use k3s on my VPS server because it is a very stable and simple K8s distribution. Upgrading is also very easy.

To upgrade to the latest stable release I simply run the command I originally used to install K3s.

curl -sfL https://get.k3s.io | INSTALL_K3S_EXEC="--disable traefik --disable servicelb" K3S_KUBECONFIG_MODE="644" sh -s -

To upgrade or downgrade to a specified K8s release e.g. v1.29.0 we use the following command:

curl -sfL https://get.k3s.io | INSTALL_K3S_VERSION=v1.29.0+k3s1 INSTALL_K3S_EXEC="--disable traefik --disable servicelb" K3S_KUBECONFIG_MODE="644" sh -s -

BTW. I accidently first upgraded to the latest version 1.30.x. The downgrade to 1.29.0 worked perfectly fine, by re-running the command with a different version :)