Emptying database after test migration

[tekojo]

Hi,

I've been working on migrating an existing forum to nodebb and have the last steps left.
I did a working test import and everything looks good.
We are running NodeBB 0.6.1 on Mongo

Now I would like to empty the database from users and discussions, while keeping all the settings I've made. The ACP is not an option, as there are quite a lot of users and discussions.

Is there a simple way to do this?