How to rerun setup?

I want to recreate the database from scratch.  How can I rerun setup?

Is there a script to create database I can run manually?  Where do I need to make changes in order to point to the new database?

Edit:

Looks like if I delete the installedplugins.txt & settings.txt from app data it will rerun.  

Yes, delete the settings.txt file and the install page will open again. The settings.txt contains the database connection string.