I’ve just tried in my own test course. Deleting a non-empty level will result in its words being lost, so don’t do that. FWIW, when there is only one level remaining (which, in your case, holds all the words), this level is removed as well, but its words remain.
Oh, and for the record: there is a “Remove Database” button, it’s located at the very bottom of the page if you load a database.
I’m actually quite astonished by the outcome of my experiments. After having removed the 2nd level, both it and the “real” one were removed. Also, the Databases button was removed along the way.
Now this posting contains instructions on how to automatically get words split into levels and I’m sure I have seen a “Create Levels” button in the past, but it seems to no longer be there.
Doing some further research I just found out that the button actually IS there. However, the website’s CSS seems to be erroneous as the button is simply off screen.
@MemriseMatty, @MemriseSupport, @kevin5284: can you please see into this?
Here’s a screenshot taken from Firefox:
The button is in the HTML though:
This also applies to Chrome, so it isn’t just Firefox.