Upgrade Instructions

Download the .ocmod.zip (either from OpenCart Marketplace, or Github and ensure you have the latest version number; unless you wish to downgrade) and upload it similarly to how you did while initially installing

Opencart 2.3.0.2:

You will be prompted with a list of files that will be "replaced" (all will be files native to this extension; click Continue to proceed)

BOTH Opencart 2.3.0.2 and 3.0.2.0:

Head to Modifications on the navigation menu -> DISABLE any previous versions of Parent Category Breadcrumbs, while leaving the latest (highest version number) active - this will not disable the extension, but only the old codebase that is cached by the system.
Also in modifications, clear cache (orange button, then blue button on the right)

Opencart 3.0.2.0:

Go to Extensions -> Installer and remove the old package (lower version numbers than what you most recently obtained from either Opencart Marketplace or Github).
Clear & refresh modification cache once again

You should now be upgraded to the latest version.