How do I associate an existing Opportunity in Salesforce with a Deal in Channeltivity?

This article pertains to customers who have the Salesforce Deal Registration integration activated.

Question:

Our Partner registered a Deal within Channeltivity. This created a corresponding Lead record in Salesforce. When converting the Lead in Salesforce, our rep decided to not create an Opportunity and instead manually created an Opportunity in Salesforce by itself. He now wants to link them after the fact. Is this possible?

Answer:

Yes, you can manually link a Deal Registration to an existing Opportunity. This article explains: How to change the linked Salesforce record