Go to the Locations overview page - https://tools.brightlocal.com/seo-tools/admin/clients-and-locations.
Find the location you want to delete, and next to the view dashboard button there is a drop down menu. Click delete location.
Once clicked a pop-up will appear, asking your preference.
If the location has reports assigned to it, you can choose to delete these at the same time or keep them.
If you delete them all the data associated to each report will be permanently deleted (yup… gone for good as well) .