How to safely remove older version of Thunderbird, and set latest version as default.

I currently have both version 68.7 and version 68.3 installed on my computer (Ubuntu 19.04). I can access the newer version from the executable in the installation directory saved to to my home directory. But, all other executables seem to point to the older version, which is a problem because trying to run the older version forces you to create a new default profile, which will then override the default profile in version 68.7, as seen in the screenshotted prompt below. So, how can I make all executable files point to only the latest installation/profile?