Thank you for taking the time posting your concern here in the Community. Are you trying to import transactions into QuickBooks Online? If so, QBO has an option to update the name using the SaasAnt app. All you need to do is connect the SaasAnt app to QBO.
I am not sure you are allowed to edit anything after the data is imported. As a workaround, import the data again and change anything before you proceed the import. Then utilize a deleter tool for your old data.