To delete a lead, navigate to a lead's page and click the symbol in the top right corner of the page.
A "Delete Lead" box will pop up.
We don't recommend you delete a lead unless it's in one of your "Invalid" stages (the gray stages on your stages and workflows page). If a lead is in any other stage ("Prospect", "Lead", "Client" or "Lost"), you should still consider it a good lead, even if it was lost at some point. Deleting it would get rid of valuable data.
Note that Invalid leads are not included on the majority of LeadSimple's reporting.