Yes following that guide will work to bring you back to a factory state
If you just did an apt-get update and didn’t continue with the Transmission install, you should be ok as that just downloads the contents of the repositories but doesn’t install anything
If you did an apt-get upgrade and proceeded, you most likely bricked the dashboard as it messes up the custom Debian OS on the MyBookLive. In this case you would need to follow that guide if you still have a working SSH connection.
Here is a much safer way to install Transmission
and I even show you how to setup an auto unrar script here
