Deals can be deleted by a user with super admin permissions. Please note, if a lead is deleted then all records of the lead will be gone PERMANENTLY. This action cannot be reversed.
Navigate to the lead or deal table and search for the customer name to be deleted. Scroll all the way to the right and click the red trash can icon to delete the record.
Deleted deals will still show in the deal pipeline view in V2 (partnername.enerflo.io/deals).
At this time, the only way to remove a deal from that view is to mark it's status as inactive rather than in progress.