How Can I Restore MarketPress Settings To Original State?

Some funny things are happening on a new site I am developing on a loca host.

I was playing around in Store Settings > Presentation > Store URL Slugs and deleted the Store Base slug.

Then I saved the settings.

Now things are a little haywire:

- Homepage is showing up with sub-menu with items that should be, I think, under Store Base - and links on the sub-menu lead to Page Not Found
- Shop on main nav bar has no sub menu and there's nothing on the page when clicked

So I think that the best thing to do would be for me to restore the plugin to its original settings - unless there's another fix I'm not aware of.

The problem is that I can't find where I can do this.

Please advise.