How to remove Joomdle from Moodle

Remove Joomdle from a Moodle test site.
Missing uninstall choice in plugins-overview.
All 5 test users are manual authentication.
I welcome your advice.

Hi.

You should get the uninstall link if you really have no users with auth=joomdle.
Got to "Manage authentication" page to confirm that you have no users with joomdle auth (Users column in the table)

Already ensured that all of the users (test users) are set to manual authentication or email-based self-authentication.

Maybe you deleted some user with joomdle auth, and it is still in the DB preventing the Uninstall link from appearing.
Look here:
tracker.moodle.org/browse/MDL-47693

You'll need to check your DB and remove the deleted users rows or change their auth method there.