Case description: you have some Magento Customer and it’s synced to the Salesforce as Contact + Account. At the some time you deside you need assign this custoemr to another Contact and Account, also all new order should go under this new Contact.
Solution: in this case you should follow next steps:
Create a new Contact and Account in the Salesforce
Assign existing Salesforce Order/Opportunity to this Account/Contact manually if you need it
Open deprecated Salesfoce Contact, find the MagentoId field. You may need make this field visible via Salesforce layouts.
Copy value defined in this field and make it empty
save changes
Go to the new Salesforce Contact
Put coppied value to the MagentoId field here
save changes
Go to the Magento Admin area
Open the “General settings“ our module page
Enable the “Developer Mode“ in the “Advanced settings“ section
Refresh Magento cache
A new “Salesforce ID Mappings“ item should appears in the “Salesforce“ menu after that
Go to the “Salesforce ID Mappings“
Find the deprecated Salesforce Ids (ContactId and AccountId) in this grid assigned to the “customer“ Magento Type
Delete these deprecated SalesfroceIDs