How to delete opportunities stages?

You can create a list of stages for your opportunities to indicate the current status of an opportunity or to track the progress of an opportunity, e.g., whether an opportunity is ongoing, lost, won or closed in the BQE CORE CRM Opportunities screen. CORE does not allow you to delete default stages such as lost, won, etc. These stages cannot be deleted as they are the default containers for all records. Check CORE Help Center for details.