How you can upgrade an existing Supertubes CLI installation depends on how you have originally installed it.
In general, you can run the following command to upgrade and install the appropriate package for your platform:
curl https://getsupertubes.sh | sh -s -- auto
If you have installed Supertubes CLI with Homebrew:
$ brew upgrade banzaicloud/tap/supertubes-cli
On Linux: Download and install the appropriate package for your distribution.