Import data into existing HubSpot properties

It would be great to have the ability to edit the content of HubSpot properties through imports or workflows.
We previously ran our NPS survey from a different platform and had HS properties to collect that data. Now that we are running surveys on HS, I’d like to be able to copy the content of those properties into the HS properties to consolidate my data and delete useless properties. Not only that, I want to run reports on NPS, and I have to exclude that historical data because the reporting tool won’t let me use both fields. Is there a workaround?