Whatever the reason, you now want to show completely different data in your existing PowerBI report. With no traces of previous data. To make this happen, you will need to do two simple steps:
- Change the credentials, i.e. Service Account
- Change the WorkspaceID parameter
You can find your current Service Account for your workspace in your Enhanza App via this link.
Make sure the correct organization is selected in the top left if you have multiple of them. The email address of your Service Account should match the desired WorkspaceID!
The key to the Service Account is generated only once when you create it. To generate a new key, you need to remove the existing Service Account and generate it again. Save your key in a safe place where you will locate it later if needed.
Generating a new key will impact only existing connections - for them, you will need to log in with a new key. But this will not impact your data in any way 
The same instructions are available if you click on the blue box Enhanza Service Account.
Visit this post to learn how to change credentials in PowerBI Desktop.
Once you are logged in under a new Service Account with a new JSON Key, you might want to change the workspaceID.
In Your PowerBI report, go to Transform data.
Depending on the version of the connector you are using, locate the “workspaceId” parameter in the bottom or in the top of the list of Queries on your left. Change this parameter to the needed WorkspaceId and press Enter.
Use “Close & Apply” button to leave the popup window.
Stay tuned, stay on top of your data, stay Enhanza