Leads: Update Details for Converted Leads in Salesforce Classic

Report on and audit converted leads with accuracy. Sales teammates with special privileges can now update fields and picklist values for leads already converted. This feature is available in Salesforce Classic only.

User Permissions Needed
To update converted leads: "Set Audit Fields upon Record Creation"

AND

"Update Records with Inactive Owners"
  1. From Setup, enter User Interface in the Quick Find box, then select User Interface.
  2. Select Enable "Set Audit Fields upon Record Creation" and "Update Records with Inactive Owners" User Permissions.
  3. Save your changes.
  4. Add the setting to your profiles. From Setup, enter Profiles in the Quick Find box, then select Profiles. Select the profile and then select Set Audit Fields upon Record Creation.
  5. Save your changes.