If you would like to delete one of your sites, you can do so by clicking on the site in the sites overview table on the dashboard of the portal.
Once you are on the page that shows you specific data of the site, click on the pen icon next to the URL on the upper left.
It will direct you down to the "Manage Website" section where you will see a red "Delete" button.
Click this button, and then confirm the deletion to permanently delete the site and all of its associated data from Patchstack.
Whenever you delete a site, it will clear up one of the slots and you will be able to add another site to your account.