1. Checkout the project
2. Set AccessKey variable in xdbHelper.aspx.cs to a random value
3. Publish to existing Sitecore solution
4. Open website in InPrivat session, open http://<your_site_name>/yourfolder/xDBHelper.aspx?key= page in the same window

Please note that you are responsible to add appropriate security measures in order to prevent others from accessing this page.