Also, check out this post, If you want to change from one system database to another after you've already run setup/installation (some also highlight below).
Run these commands:
$ php artisan config:clear
$ php artisan cache:clear
$ php artisan dreamfactory:setup
//Answer the on screen prompts
To my knowledge the uninstaller doesn’t leave anything behind, but if you install another instance on the same machine, you may need to do things like clear the browser cache. Because your browser will keep trying to use an old session cookie.
Let me know how this works for you.