Change connectionstring from tenant

Hi all, Currently we are working on a migration of Power BI from Office 365 tenant A to Office 365 tenant B. Datasets that resides within Office 365 tenant A will be moved to tenant B. So far so good, but there are several Excel reports that are connected to Power BI datasets. Is there a way to change the connection string of the Excel reports so we can change the source from the dataset from tenant A to tenant B? We do not want to recreate the reports and ofcourse the datasets are exactly the same within tenant A and tenant B.