6 answers
You can use a tool like Dataloader.IO or Apex Data Loader and perform a delete operation on the OpportunityContactRole object.
You can use an SOQL Query like this to get access to Contact Roles associated with "open" Opportunities and then perform an Export.
SELECT Id FROM OpportunityContactRole WHERE Opportunity.IsClosed = FALSE
Then use the same CSV to run a
Delete on the OpportunityContactRole object.